Potato (Solanum tuberosum L.) is the world’s fourth-largest staple crop. Alkaline salt stress is a major abiotic stress factor that severely limits the growth, yield, and quality of potatoes; however, little is known about the molecular basis of potatoes’ response to alkaline salt stress or the stress-alleviation mechanism mediated by 24-epibrassinoside. In this study, we conducted a genome-wide identification of the potato miR482 family and analyzed its response patterns under alkaline salt stress and 24-epibrassinoside-mediated stress relief. We identified a total of 9 mature stu-miR482 sequences and 5 precursor sequences; all precursors form typical stable hairpin structures and exhibit high evolutionary conservation among Solanaceae plants. Promoter analysis revealed multiple cis-acting elements in the promoter region associated with light signaling, plant hormones, and stress signaling. A total of 64 potential target genes were predicted, encompassing transcription factors, disease resistance, and signal transduction-related genes, forming a complex regulatory network. Phenotypic analysis confirmed that EBR significantly alleviates the growth inhibition in potatoes induced by alkaline salt stress. qRT-PCR analysis indicated that stu-miR482a-5p is the primary stress-responsive member in leaves; stu-miR482d-3p/5p exhibited the strongest regulatory response to EBR in roots; in potato stolons, all members of the miR482 family were significantly upregulated under alkaline salt stress, with stu-miR482d-5p showing extremely significant upregulation across all treatment groups. In summary, this study represents the first systematic characterization of the potato miR482 family, revealing its tissue differential functions in alkaline salt stress and EBR-mediated stress relief.

Saline-alkali soils significantly constrain agricultural productivity, demanding effective remediation approaches. This study systematically investigated the individual and combined effects of plastic mulching (M) and microbial fertilizer (F) on soil microbial activity, metabolic profiles, and potato yield under saline-alkali conditions. The combined treatment (MF) resulted in substantial improvements in soil health, including a 181.8% increase in organic matter, elevated total nitrogen (49.7%), phosphorus (37.8%), and potassium (21.9%), along with enhanced nutrient availability. MF also increased microbial biomass carbon (21.8%), nitrogen (150.0%), and phosphorus (38.3%), boosted key enzyme activities by 17.0-85.7%, and reduced soil pH (5.9%) and salt content (27.8%). These improvements led to a 2.4-fold higher soil quality index and a 57.0% increase in potato yield. Metabolomic analysis identified 8 key metabolites involved in critical pathways such as ABC transporters and purine metabolism. Structural equation modeling revealed that soil enzyme activities and metabolites are major drivers enhancing soil quality and yield, with soil quality being the primary factor determining productivity. These findings demonstrate that MF alleviates saline-alkali stress by synergistically regulating soil enzyme activities and metabolic pathways. This study provides a sustainable strategy for improving saline soil productivity. One future direction is to include treatments with individual microbial agent to quantify their specific contributions and disentangle their interactive effects.

Objective:This study aims to investigate the effects of legume crop rotation on the rhizosphere microbiota and its potential to improve potato (Solanum tuberosum L.) productivity and tuber quality. We specifically focus on the microbial functional potential revealed through metagenomic sequencing under different legume rotation systems in the intensive agricultural region of the Chinese Loess Plateau. Methods:A five-year field experiment (2018-2022) was conducted to establish three cropping systems: (1) continuous potato monocropping for 5 years (CK), (2) continuous potato cropping for 3 years followed by one-year pea rotation and one-year potato cropping (T1), and (3) continuous potato cropping for 3 years followed by one-year faba bean rotation and one-year potato cropping (T2). The impacts of these rotation regimes on potato yield formation, tuber quality, and rhizosphere microbial communities were systematically evaluated, with a focus on microbial diversity and functional potential, using metagenomic sequencing and network analysis. Results:Metagenomic analysis demonstrated that legume rotation, particularly the T2 system, significantly enriched the relative abundances of Actinobacteria (38.31%) and Proteobacteria (28.40%) in the potato rhizosphere while reducing Acidobacteria (10.03%). Functional annotation further revealed that T2 promoted the expression of microbial genes involved in carbon fixation (K00626, K01895, etc.), nitrogen assimilation (narB, narA, etc.), and sulfur metabolism (cysNC, cysN, etc.), enhanced potential for nutrient cycling. Co-occurrence networks revealed Actinobacteria and Acidobacteria as keystone taxa forming robust interaction modules potentially linked to soil ecological stability. Compared to CK, T2 increased the commercial tuber rate by 85.82%, overall tuber yield by 28.38%, starch content by 34.85%, and vitamin C content by 30.79%, while reducing sugar levels decreased by 9.35%. Conclusion:Faba bean-potato rotation (T2) effectively mitigated the adverse impacts caused by continuous potato cropping by altering the rhizosphere microbial structure and enhancing microbial functional pathways related to nutrient cycling. This study provides a detailed metagenomic perspective on the microbial mechanisms underlying the benefits of crop rotation and offers a theoretical basis for developing microbiome-informed ecological management strategies to mitigate continuous cropping obstacles in potato production on the Loess Plateau.

Multiparent populations are now widespread in crop genetic studies as they capture more genetic diversity and offer high statistical power for detecting quantitative trait loci (QTLs). To confirm the suitability of using a recently developed chickpea (Cicer arietinum L.) multi-parent advanced generation intercross (MAGIC) population for genetic studies, we characterized the diversity of the eight founder lines and explored the linkage disequilibrium decay, marker coverage, segregation distortion, allelic variation, and structure of the population. The MAGIC population was genotyped using whole-genome sequencing; following marker curation, a total of 4255 high-quality polymorphic single nucleotide polymorphism markers were used for genomic analyses. To demonstrate the effectiveness of the MAGIC population to dissect the genetics of key agronomic traits (days to 50% flowering and plant height), we employed both a genome-wide mapping approach using fixed and random model circulating probability unification and a haplotype-based mapping using the local genomic estimated breeding value approach. Our analyses confirmed the role of genomic regions previously reported in the literature and identified several new QTLs for days to 50% flowering and plant height. We also showed the potential for trait improvement through stacking the top 10 haploblocks to develop early flowering chickpea and selection of desirable haplotypes on chromosome 4 to improve plant height. Our results demonstrate the chickpea MAGIC population is a valuable resource for researchers and pre-breeders to study the genetic architecture of complex traits and allelic variation to accelerate crop improvement in chickpea.

Land salinization severely limits the development of agriculture, and the growing global population poses a serious challenge to food security. As an abiotic stress factor limiting photosynthesis in potatoes (Solanum tuberosum L.), alkaline salt stress significantly impacts their photosynthetic activity. In this study, potted seedlings of the ‘Atlantic’ variety were planted in the pots. Sodium bicarbonate (NaHCO3) was incorporated into the dry soil within the pots at four distinct concentration levels: 0 mmol/L, 20 mmol/L, 40 mmol/L, and 60 mmol/L. The findings indicated that at a concentration of 60 mmol/L, the initial fluorescence (Fo) exhibited its peak value. At this concentration, NaHCO3 stress induced a significant decline in several parameters: variable fluorescence (Fv), the chlorophyll fluorescence ratio (Fv/Fm), dark-adapted maximum fluorescence (Fm), the Fv/Fo ratio, and overall plant performance. Compared to the control CK, the values of Fv, Fv/Fm, Fm, and Fv/Fo decreased by 42.36%, 20.44%, 54.1%, and 61.97%, respectively. At a stress concentration of 60 mmol/L, NaHCO3 stress exhibited a more pronounced inhibition of chlorophyll synthesis. Under T3 treatment at this stress concentration, the contents of chlorophyll a, chlorophyll b, and total chlorophyll a/b were significantly lower than the control group (CK), decreasing by 46.29%, 54.3%, and 48.56%, respectively. The T2 treatment showed the next most pronounced reduction, with levels 33.26%, 45.75%, and 36.79% lower than CK, respectively. After a brief increase in the intercellular CO2 concentration (Ci) in photosynthetic gas exchange, the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) decreased significantly with the gradual increase in concentration and prolongation of time. The expression levels of genes related to some subunits of photosystem II and photosystem I were down-regulated under stress, while the expressions of genes related to Fd and FNR were also down-regulated to varying degrees. In this study, photosynthetic activities such as fluorescence parameters, chlorophyll content, and photosynthetic gas exchange were measured, along with 16 key photosynthetic genes of potato plants. The aim was to explore the effects of alkaline salt stress on potato photosynthesis and its related mechanisms. The research outcomes contribute to a better understanding of potato’s adaptive responses to alkaline stress, potentially informing future efforts in crop improvement and saline agriculture management.

Saline-alkali stress severely impacts global crop productivity, while basic leucine zipper (bZIP) transcription factors (TFs) are known regulators of abiotic stress responses, the specific mechanisms of StbZIP1 in potato saline-alkaline tolerance remains unclear. We cloned StbZIP1 from tetraploid potato ‘Favorita’, analyzed its sequence characteristics, and generated overexpression lines. StbZIP1-overexpressing (OE) and wild-type (WT) plants were subjected to saline-alkaline stress (NaCl: NaHCO3 = 1:1) to assess physiological and molecular responses. StbZIP1 encodes a 16.61 kDa protein with conserved bZIP domains. Secondary structure prediction revealed that the protein comprises 55.48

In the arid and semi-arid zones of Northwest China, soil drought and alkaline salt stress often occur simultaneously and affect plant growth at multiple levels. Potato (Solanum tuberosum L.) is a food crop sensitive to drought and alkaline salt stresses and is susceptible to yield loss due to environmental impacts. In recent years, most of the research on abiotic stress response in potato has focused on drought and saline single stresses, and the mechanism of potato response to combined drought-alkaline salt stress and its interactions are still unclear. Therefore, a pot experiment was designed in this study and the potato variety 'Atlantic' was selected as the test material. The effects of drought (25 % PEG-6000), alkaline salt (200 mmol & sdot;L-1 NaHCO3) and combined drought- alkaline salt (25 % PEG-6000 + 200 mmol & sdot;L-1 NaHCO3) stresses on growth traits, micro- and ultrastructure, reactive oxygen species, osmoregulatory substances, and antioxidant defenses of potato were investigated using no stress (CK) as a control, leaf photosynthesis and endogenous plant hormones, and also analyzed the changes in the expression patterns of genes related to plant hormone signal transduction under different stresses. The results showed that drought, alkaline salt, and combined stress affected growth, leaf anatomy, and photosynthesis, and increased the accumulation of osmoregulatory substances in potato. The scavenging activities of antioxidant compounds and antioxidant enzymes were enhanced in potato, and combined stress treatments significantly damaged potato more than single stresses. In 2022, combined stress caused a marked increase in H2O2 (208.7 %) and O2- (455.6 %) content, while in 2023, they increased by 87.5 % and 215.7 %, respectively. SOD, POD, CAT, TPX, APX, GR, GPX and DHAR enzyme activities were increased by 209.13 %, 55.19 %, 152.59 %, 47.13 %, 104.02 %, 347.37 %, 68.45 % and 130.69 % in 2022 compared to CK in the combined stress treatment. In 2023, they increased by 229.81 %, 49.95 %, 160.62 %, 102.16 %, 94.06 %, 505.15 %, 47.00 %, and 121.19 %, respectively. After the stress treatments, the contents of gibberellic acid (GA3) and auxins (IAA) were significantly lower than those in CK, whereas the contents of abscisic acid (ABA), salicylic acid (SA), and brassinosteroids (BRs) increased. Expression of IAA-related genes (AUX1, Aux/IAA, GH3, and SAUR) was up-regulated after stress. ABA-related genes (PYR/PYL, SnRK2, and ABF) were up-regulated after stress, whereas protein phosphatase 2C (PP2C) genes were down-regulated in expression after stress. The GA3 receptor GID1 and the Fbox protein GID2 were up-regulated after stress. Xyloglucosyl transferase TCH4 gene was up-regulated by stress and positively correlated with changes in BRs content. The TGA transcription factor, PR-1 gene, was induced to up-regulate its expression by stress and positively correlated with changes in SA content. Drought, alkaline salt, and combined stress reduced potato tuber yield and quality, which were 54.13 % and 60.14 % lower than CK in combined stress treatments in 2022 and 2023, respectively, which were significantly correlated with changes in physiological and biochemical characteristics and hormone contents of potato plants.

ABSTRACTAlkaline salt stress, as a more diverse stress, severely affects the growth and development of potato (Solanum tuberosum L.) and leads to yield reduction. Brassinosteroids have been shown to regulate plant growth and play an essential role under environmental stress. However, the physiological responses by which brassinosteroids confer alkaline salt stress tolerance in potato remain unclear. We used potato ‘Atlantic’ as experimental material. The effects of 0.01, 0.1, 1 and 10 μmol·L−1 of 24‐epibrassinolide (EBR) on the physiological and photosynthetic characteristics of potato under alkaline salt stress (300 mmol·L−1 NaHCO3) were studied. The results showed that exogenous EBR increased the antioxidant enzyme activities, increased the content of osmoregulatory substances and decreased the production of peroxidation products in potato leaves under alkaline salt stress. EBR treatment improved the photosynthetic characteristics by accumulating more photosynthetic pigments. This was manifested by an increase in net photosynthetic rate, transpiration rate and stomatal conductance, and a decrease in intercellular carbon dioxide concentration. In addition, exogenous EBR increased the maximal quantum yield of photosystem II photochemistry and the effective PSII quantum yield of potato PSII under alkaline salt stress and ultimately increased yield. Potato tuber yield was significantly increased by 27.31% and 29.17% in T4 treatment compared to T1 in 2022 and 2023, respectively. Cluster and correlation analyses further demonstrated the beneficial effects of exogenous EBR on physiology, photosynthetic characteristics and potato yield under alkaline salt stress. In conclusion, exogenous EBR can enhance the tolerance of potato to alkaline salt stress by improving the antioxidant system and photosynthesis.

Transcriptome proteome association analysis screened candidate DEGs, DEPs, and DEGs/DEPs associated with potato response to drought, alkali, and combined stresses. Overexpression of StCOMT1 enhances potato drought and alkali tolerance. Drought and salinity have severely impeded potato (Solanum tuberosum L.) growth and development, significantly reducing global potato production. However, the molecular mechanisms regulating the combined drought and alkali stress process are not fully understood. This study compared the mRNA and protein expression profiles of potato under drought (PEG-6000), alkali (NaHCO3), and combined (PEG-6000 + NaHCO3) stresses by transcriptome and TMT proteomics sequencing to investigate the common or specific responses of 'Atlantic' potato to single and combined stresses of drought and alkali were preliminarily explored. It was found that 2215 differentially expressed genes (DEGs) and 450 differentially expressed proteins (DEPs) were jointly identified under drought, alkali, and combined stresses. Under drought, alkali, and combined stresses, 234, 185, and 246 DEGs/DEPs were identified, respectively. These DEGs, DEPs, and DEGs/DEPs identified revealed the potential roles of several signaling and metabolic pathways in mediating drought and alkali stress tolerance, including plant hormone signaling, MAPK signaling pathway, phenylpropanoid biosynthesis, and glutathione metabolism. Caffeic acid-O-methyltransferase (COMT) is an essential methylating enzyme in the phenylpropane biosynthetic pathway, which is involved in lignin synthesis and plays an important role in protecting plants from abiotic stresses. In this study, we investigated the changes in physiologic characteristics, such as growth, antioxidant defense, osmotic regulation and lignin accumulation, in overexpressing StCOMT1 (PT0001512/M0ZIL7) transgenic potato after stress. It proved that the gene has the function of adapting to drought and alkali stress, and provided a theoretical basis for further research on the resistance mechanism of the gene in drought and alkali tolerance in potato.

Saline–alkali stress severely inhibited potato growth, yield, and quality, and exogenous abscisic acid (ABA) played an important role in plant stress resistance. In this study, potato tissue culture seedlings were used as experimental materials, the control group was cultured in the MS medium without adding any substances, and the treatment group was cultured in MS medium supplemented with 50 mmol/L NaHCO3 or 50 mmol/L NaHCO3 + 38 µM ABA, respectively. To explore the effect of exogenous ABA on the biological characteristics of potato plants under saline–alkali stress, a genetic improvement strategy was designed based on PP2C (PGSC0003DMT400046381), a key gene of the ABA signaling pathway. The results showed that saline–alkali stress led to leaf greening, wilting, and root development stunting, while exogenous ABA treatment significantly alleviated stress damage. PP2C negatively regulates ABA signaling. SnRK2s are activated when PP2Cs are inactivated during the ABA response. Compared with wild-type CK, it was found that TG lines had increased SOD and POD activities, increased carotenoid and ABA contents, reduced the increase in Na+ content and the decrease in K+ content, and interfered with PP2C (PGSC0003DMT400046381) to significantly enhance potato salinity–alkali resistance. This study provides a theoretical basis and technical path for the analysis of ABA-mediated plant stress resistance mechanism and the breeding of potato stress resistance varieties.

Drought and alkaline salt stress act synergistically on potato, affecting growth and causing reduced yield and quality. Lignin plays a key role in potato resistance to abiotic stresses, and most of the key enzymes in its synthetic pathway were involved in plant stress response. Among them, caffeoyl CoA O-methyltransferase (CCoAOMT) is a key enzyme for G-type lignin synthesis, and the StCCoAOMT gene is involved in potato lignin synthesis and response to plant stress in response to adversity. The study identified 13 StCCoAOMT genes, which were classified into four subgroups by evolutionary analysis. We have analyzed their physicochemical properties, gene structures, motifs, and cis-acting elements. StCCoAOMT family genes are subject to purification selection, and tandem repeats are the primary driver of gene duplication. The collinearity relationships with other species analysis showed that the StCCoAOMT genes are evolutionarily distinct from monocotyledonous plants. Through transcriptomic analysis and RT-qPCR validation of the tissue-specific expression patterns of StCCoAOMT genes under drought, alkaline salt, and combined stress conditions, we identified the stress-responsive gene StCCoAOMT7.We also obtained the homologous gene, StCCoAOMT1, which has the highest degree of similarity to the Arabidopsis thaliana gene At4g34050, which is responsive to drought and salt stresses, by sequence comparison. VIGS analysis revealed that NbCCoAOMT1 and NbCCoAOMT7 silenced tobacco plants displayed reduced resistance compared to WT plants under drought, alkaline salt, and combined stress. It is speculated that the StCCoAOMT1 and StCCoAOMT7 genes positively regulate drought, alkaline salt, and combined stress. The subcellular localization of StCCoAOMT1 and StCCoAOMT7 proteins was investigated in tobacco. The results indicate that both proteins may function in the nucleus, plasma membrane, and cytoplasm, providing new insights into the molecular mechanisms underlying plant defense and stress responses. StCCoAOMT1 and StCCoAOMT7 were screened as drought, alkaline salt, and combined stress response genes.

Soil bacteria drive biogeochemical cycles and influence disease suppression, playing pivotal roles in sustainable agriculture. Using Illumina MiSeq sequencing, we assessed how six ridge-furrow film mulching patterns affect soil bacterial diversity in a continuous potato system. The Shannon index showed significantly higher diversity in fully mulched treatments (T2–T3) versus controls (CK), suggesting mulching enhances microbial community richness. This result suggests that complete mulching combined with ridge planting (T2) may significantly enhance bacterial proliferation in soil. The bacterial communities were predominantly composed of Acidobacteria, Pseudomonadota, Bacteroidota, Chloroflexota, and Planctomycetota. Among these, Acidobacteria showed the highest abundance, with ridge planting patterns favoring greater Acidobacteria richness compared to furrow planting. In contrast, Pseudomonadota exhibited higher abundance under half-mulching conditions than under complete mulching. At class level, Acidobacteria and Proteobacteria emerged as the most abundant groups, with Proteobacteria constituting 22.6–35.7% of total microbial populations. Notably, Proteobacteria demonstrated particular dominance under the complete mulching with ridge planting pattern (T2). At the genus level, Subgroup_6_norank represented the most dominant taxon among the 439 identified bacterial genera, accounting for 14.0–20.2% of communities across all treatments, with half-mulching ridge planting (T4) showing the highest relative abundance. Our findings demonstrate that different ridge-furrow film mulching patterns significantly influence soil microbial diversity. While traditional non-mulched (CK) and mulched flat plots (T1) exhibited similar impacts on bacterial community structure, other treatments displayed distinct taxonomic profiles. Complete mulching patterns, particularly ridge planting (T2), appear most conducive to microbial development, suggesting their potential to enhance soil biogeochemical cycling in continuous cropping systems. These results provide valuable insights for optimizing mulching practices to improve soil health in agricultural ecosystems.

Abstract Mungbean is an important sub‐tropical legume crop grown across Asia, Africa, and Australia. Yield improvement is crucial for expanding production, but phenotyping important traits across diverse environments using current approaches is challenging, limiting the scale and complexity of information captured. High‐throughput phenotyping platforms offer a solution by rapidly screening traits at scale. This study deploys an unmanned aerial vehicle (UAV) platform to determine the potential of phenotyping a range of agronomic and physiological traits within a diverse mungbean population evaluated across three field trials. Three predictive data‐driven modeling approaches were undertaken to evaluate performance accuracy in predicting these traits: linear regression, stepwise regression, and partial least squares regression. Results show that using the geometric trait “coverage” as a proxy is most suitable for screening visual traits like early vigor. For functional traits (i.e., aboveground biomass), predictive data‐driven models demonstrate high accuracy during early‐ and mid‐canopy development stages (R2 0.79, root mean square error [RMSE] 4.08 and R2 0.8, RMSE 26.92, respectively), but accuracy declines in late‐canopy development (R2 0.33 and RMSE 43.15). Prediction accuracy can be optimized by using different modeling approaches at different stages during the transition from early‐ to mid‐canopy development as well as canopy closure. Similar findings were observed when examining the prediction models for the physiological trait, stomatal conductance (R2 0.69 and RMSE 0.10). These approaches are expected to enable breeders and researchers to incorporate UAV‐based phenotyping systems into mungbean improvement programs. Such approaches might be most efficiently used at scale if applied as part of a “real‐time” calibration approach.

Abstract Background GAox is a key enzyme involved in GA biosynthesis pathway and plays an important role in regulating various processes in plant life cycle. However, it has not been systematic, studies have been conducted in potato, which is the world's fourth largest food crop. Methods In this work, we systematically identified GAox gene family (StGAox) in potato by analyzing the potato genome sequence using a set of bioinformatics approaches, and analyze their physical, chemical properties, distribution on chromosomes, gene structure, conserved motifs, gene duplication events and expression patterns were analyzed. Results The results showed that a total of 33 GAox proteins were identified and unevenly distributed on 10 chromosomes. Based on their protein structure and phylogenetic characteristics, these 33 StGAoxes were divided into 5 distinct subclasses. Collinearity analysis revealed that there were 5 pairs of duplicated genes in the StGAox gene family, and all of which evolved under purifying selection. Analysis of RNA-seq data of double haploid (DM) potatoes under different tissues, abiotic stresses and hormone treatments showed that PG0002068, PG0024249 and PG0027963 were higher expressed in leaves, PG009427, PG0026762, PG0009021 and PG0021095 were higher expressed in tubers, PG2003479, PG0024249, PG0005698, and PG0009021were higher expressed in shoots than those of other tissues. In addition, the expression of PG0002068, PG2003479, PG0032156, PG0024249, and PG0021292 were up-regulated under mannitol and drought stress. Conclusions Comparative genome-wide analysis of StGAox genes and their expression analyses revealed that members of this family may be involved in tissue-specific developmental and abiotic stress responses. Graphical Abstract

Heat and drought stresses usually occur together in nature, and both are expected to increase in frequency and intensity as a result of climate change. The synergistic impacts of these compound climate extremes on potatoes are far from the effects of individual stresses. However, the dynamics of the effects of combined heat and drought stresses on potato physiology and biochemistry have yet to be thoroughly assessed. To elucidate this point, we set up a pot experiment using ‘Atlantic’ potato seedlings as test material. A total of six treatments were set up: CK (normal growth conditions: 21 ℃, 0 PEG), A1B1 (31 ℃, 20

Mungbean is an important source of plant protein for consumers and a high-value export crop for growers across Asia, Australia and Africa. However, many commercial cultivars are highly vulnerable to biotic stresses, which rapidly reduce yield within the season. Fusarium oxysporum is a soil-borne pathogen that is a growing concern for mungbean growers globally. This pathogen causes Fusarium wilt by infecting the root system of the plant resulting in devastating yield reductions. To understand the impact of Fusarium on mungbean development and productivity and to identify tolerant genotypes, a panel of 23 diverse accessions was studied. Field trials conducted in 2016 and 2021 in Warwick, Queensland, Australia under rainfed conditions investigated the variation in phenology, canopy and yield component traits under disease and disease-free conditions. Analyses revealed a high degree of genetic variation for all traits. By comparing the performance of these traits across these two environments, we identified key traits that underpin yield under disease and disease-free conditions. Aboveground biomass components at 50 % flowering were identified as significant drivers of yield development under disease-free conditions and when impacted by Fusarium resulted in up to 96 % yield reduction. Additionally, eight genotypes were identified to be tolerant to Fusarium. These genotypes were found to display differing phenological and morphological behaviours, thereby demonstrating the potential to breed tolerant lines with a range of diverse trait variations. The identification of tolerant genotypes that sustain yield under disease pressure may be exploited in crop improvement programs.

Abstract Background Potato (Solanum tuberosum L.) production is seriously threatened by the oomycete Phytophthora infestans (P. infestans). However, it remains unclear how the two potato cultivars, Q9 (moderately resistant) and Atl (susceptible), initiate distinct defense responses after inoculation with P. infestans. To uncover the underlying process, we investigated the dynamic gene expression profiles and the functions of the differentially expressed genes (DEGs). Results The results showed that the numbers of up-regulated DEGs were 1345, 1063 and 1694 in Q9 and 272, 603 and 2554 in Atl at 1 day post inoculation (dpi), 3 dpi and 5 dpi, respectively. Meanwhile, the down-regulated DEGs were 1557, 1417 and 389 in Q9 and 114, 364 and 2528 in Atl simultaneously. KEGG enrichment analysis revealed that plant-pathogen interaction, phenylpropanoid biosynthesis and MAPK signaling pathway were significantly enriched in Q9 at the later stage. Furthermore, DEGs associated with plant-pathogen interaction and phenylpropanoid biosynthesis showed higher expression levels in Q9 compared to Atl, especially at the later stage. The expressions of eight DEGs were validated by quantitative real-time PCR (qRT-PCR), which further verified the accuracy of the transcriptomics analysis. In addition, DEGs that were exclusively up-regulated and down-regulated in Q9 were analyzed, which may contribute to the resistance of Q9. Transient expression analysis revealed that four DEGs, including StHP1, StMYB2, StHSP3 and StNAC5, exhibited increased tolerance to P. infestans, indicating a positive role in enhancing the resistance of Q9. Conclusion Therefore, the DEGs associated with plant-pathogen interaction, phenylpropanoid biosynthesis and MAPK signaling pathway were involved in regulating late blight, and the expression level of the related genes significantly increased in Q9. In addition, StHP1, StHSP3 and the transcription factors, including StMYB2 and StNAC5, played positive roles in improving the resistance of potato Q9 to P. infestans. These findings provide useful information for further understanding the molecular mechanism of potato resistance to late blight. Furthermore, our study identified novel resistance genes that can be used in resistance breeding and functional research. Graphical abstract

Seminal root angle (SRA) is an important root architectural trait associated with drought adaptation in cereal crops. To date, all attempts to dissect the genetic architecture of SRA in durum wheat (Triticum durum Desf.) have used large association panels or structured mapping populations. Identifying changes in allele frequency generated by selection provides an alternative genetic mapping approach that can increase the power and precision of QTL detection. This study aimed to map quantitative trait loci (QTL) for SRA by genotyping durum lines created through divergent selection using a combination of marker-assisted selection (MAS) for the major SRA QTL (qSRA-6A) and phenotypic selection for SRA over multiple generations. The created 11 lines (BC1F2:5) were genotyped with genome-wide single-nucleotide polymorphism (SNP) markers to map QTL by identifying markers that displayed segregation distortion significantly different from the Mendelian expectation. QTL regions were further assessed in an independent validation population to confirm their associations with SRA. The experiment revealed 14 genomic regions under selection, 12 of which have not previously been reported for SRA. Five regions, including qSRA-6A, were confirmed in the validation population. The genomic regions identified in this study indicate that the genetic control of SRA is more complex than previously anticipated. Our study demonstrates that selection mapping is a powerful approach to complement genome-wide association studies for QTL detection. Moreover, the verification of qSRA-6A in an elite genetic background highlights the potential for MAS, although it is necessary to combine additional QTL to develop new cultivars with extreme SRA phenotypes.

AbstractOptimal root system architecture (RSA) is critical for efficient resource capture in soils, hence being an interest in crop breeding. Seminal root angle (SRA) at the seedling stage in durum wheat has been suggested to be a good indicator of RSA. However, research on correlating such laboratory‐based seedling root phenotyping to RSA at later phases of plant growth is limited, resulting in the importance of root trait variation seen in seedlings often being overstated. To explore the role of SRA in modifying RSA at later phases of plant growth, we assessed 11 genotypes contrasting in SRA (wide and narrow), grown in a rhizobox designed for phenotyping root systems of plants during late‐tillering. Aboveground traits and root dry mass in different soil depths and across the entire soil volume were measured manually, while root architectural traits were extracted using image analysis and summarised by multiple factor analysis to describe RSA. When comparing the wide and narrow genotypes, no differences were detected for aboveground traits and total root dry mass. However, differences were observed in the allocation of root dry mass at different depths. The wide and narrow genotypes showed distinct RSAs, particularly in the upper soil (0–30 cm). The wide genotypes exhibited a ‘spread‐out’ root system with dense and thin roots, whereas the narrow genotypes had a compact root system with fewer but thicker roots. Our study demonstrated a clear difference in RSA between the wide and narrow genotypes, highlighting the association between SRA on the direction and distribution of root growth in plants at later growth stages.

Background With the rapid development of the economy and society, soil pollution is becoming more and more serious. Heavy metal cadmium (Cd) pollution is one of the typical problems, which poses a potentially serious threat to crop production and human health. Cinnamyl alcohol dehydrogenase (CAD) is a key enzyme in lignin synthesis and plays an important role in plant resistance to external stress. In this study, combined with bioinformatics analysis and expression pattern analysis, the members of the potato CAD family were identified, and their physical and chemical properties, evolutionary characteristics and chromosome location were clarified, as well as their regulatory effects on Cd tolerance. Results A total of 50 StCAD genes belonging to 6 subfamilies were obtained, and all of them were located in the cytoplasm. Members of the same family had similar gene structures and functional domains. The promoter region of each StCAD family member contains at least 5 or more abiotic stress response elements, indicating that the family had potential functions in regulating stress. According to the expression pattern analysis, most genes in this family were upregulated after Cd stress, further enhanced CAD activity and significantly promoted lignin accumulation in potato roots. Conclusion In summary, the StCAD family plays an important role in potato response to Cd stress. This study lays a foundation for further studies on the functions of the StCAD family and provides candidate genes for Cd resistance molecular breeding in potato. Graphical Abstract