Phosphorus (P) is an essential macronutrient for plant growth and development. Root hairs enhance P acquisition as inorganic phosphate (Pi) from soil by expanding the root surface area, and their elongation is a key adaptive response to low Pi availability. However, the transcriptional regulators that couple Pi starvation signaling to root hair elongation remain largely unknown. Here, we demonstrate that PHOSPHATE STARVATION RESPONSE1 (PHR1), the central transcription factor of the Pi starvation response, positively regulates Pi deficiency-induced root hair elongation in Arabidopsis. RNA-seq analysis of root tips identified ROOT HAIR DEFECTIVE 6-LIKE 2 (RSL2), a bHLH transcription factor governing root hair elongation, as a prominent PHR1-regulated target. We show that PHR1 binds to the promoter of RSL2 to activate its expression, and genetic analysis confirms that RSL2 acts downstream of PHR1. Further RNA-seq analysis revealed that RSL2 regulates cell wall remodeling genes, among which XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE 26 (XTH26) was identified as a key target. RSL2 binds to the promoter of XTH26 to upregulate its transcription, and XTH26 overexpression partially rescues the reduced root hair length of both phr1 and rsl2. Collectively, our findings delineate a PHR1-RSL2 transcriptional module that orchestrates root hair elongation under Pi deficiency, thereby contributing to enhanced Pi acquisition.

Arsenic (As) contamination poses a significant threat to crop production and food safety. In plants, arsenate [As(V)] is taken up into cells through phosphate transporters due to their chemical similarity, where it disrupts metabolic processes and causes oxidative stress. However, the precise role of phosphate transporters in As accumulation and tolerance remains unclear. Here, we investigated the function of BnPHT5;1b, a vacuolar phosphate influx transporter in Brassica napus. Double mutants of two BnPHT5;1b genes, BnA09.PHT5;1b and BnCn.PHT5;1b (hereafter referred to as BnPHT5;1b DM) exhibited enhanced tolerance to As(V) at the seedling stage, showing increased biomass, longer roots, and higher chlorophyll content under As stress. Transcriptome analysis revealed that both wild-type and mutant plants activated oxidative stress responses, but the BnPHT5;1b DM displayed stronger enrichment of antioxidant and detoxification pathways. Importantly, disruption of BnPHT5;1bs promoted root-to-shoot As translocation, with xylem sap As(III) and As(V) increased by 51.0% and 75.0%, respectively, and As concentrations in cotyledons, old leaves, and new leaves increased by 61.3%, 153.7%, and 129.7%, respectively. This was accompanied by 6.8-fold higher As accumulation in shoot cell walls, while seed As levels remained similar to or slightly lower than those of wild-type. These findings establish BnPHT5;1b as a key regulator of As transport and detoxification in B. napus. This study reveals a previously unrecognized strategy for enhancing arsenate tolerance while promoting root-to-shoot As translocation and shoot cell wall retention without increasing seed As accumulation, providing a potential genetic resource for phytoremediation of As-contaminated soils.

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.

Mulching is an important measure to conserve moisture and increase yield in dryland orchards of the Loess Plateau, and it is critical to realize high and stable yield and sustainable development of fruit crops. Based on field positioning obervation, the comprehensive effects of different mulching methods on soil water storage, fruit tree growth and physiological status, yield were investigated. Treatments were straw mulching (SM), horticultural fabric mulching (BF), black plastic film mulching (BM), white plastic film mulching (WM) and no mulching (CK). The results showed that: (1) Compared with CK, different mulching measures can significantly increase the average soil water storage in the 0-120 cm soil layer during the whole reproductive period, which can provide a basis for the realization of inter-temporal water regulation; (2) Different mulching methods can significantly increase the growth of apple branches and LAI, and enhance the tree strength; (3) SM, BF, and BM can significantly increase the net photosynthetic rate, and BM inhibited the occurrence of midday depression; (4) Under the BF treatment, the yield, the anthocyanin content, the soluble sugar content, sugar-acid ratio and fruit hardness were higher than CK. Using the comprehensive scoring method to obtain BF as the optimal mulching method, so BF was an appropriate technique to improve the hydrological status, fruit yield and quality of apple orchard soil in the Loess Plateau.

High-quality genome information is essential for efficiently deciphering and improving crop traits. Here, we report a highly contiguous and accurate hexaploid genome assembly for the key wheat breeding parent Zhou8425B, an elite 1BL/1RS translocation line with durable adult plant resistance (APR) against yellow rust (YR) disease. By integrating HiFi and Hi-C sequencing reads, we have generated a 14.75-Gb genome assembly for Zhou8425B with a contig N50 of 70.94 and a scaffold N50 of 735.11 Mb. Comparisons with previously sequenced common wheat cultivars shed light on structural changes in the 1RS chromosome arm, which has been extensively used in wheat improvement. Interestingly, Zhou8425B 1RS carries more genes encoding AP2/ERF-ERF or B3 transcription factors than its counterparts in four previously sequenced wheat and rye genotypes. The Zhou8425B genome assembly aided in the fine mapping of a new APR locus (YrZH3BS) that confers resistance to YR disease and promotes grain yield under field conditions. Notably, pyramiding YrZH3BS with two previously characterized APR loci (YrZH22 and YrZH84) can further reduce YR severity and enhance grain yield, with the triple combination (YrZH3B + YrZH22 + YrZH84) having the greatest effect. Finally, the founder genotype effects of Zhou8425B were explored using publicly available genome resequencing data, which reveals the presence of important Zhou8425B genomic blocks in its derivative cultivars. Our data demonstrate the value of the Zhou8425B genome assembly for further study of the structural and functional characteristics of 1RS, the genetic basis of durable YR resistance, and founder genotype effects in wheat breeding. Our resources will facilitate the development of elite wheat cultivars through genomics-assisted breeding.

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.

Abstract: Mulching and supplementary irrigation are commonly used water-saving techniques ensuring agricultural sustainability in drylands of northwest China. However, the effects of the combination of mulching and supplementary irrigation on the soil environment, and the growth of apple trees remain unclear. Field experiments were conducted in 2023 to evaluate the effects of the combination of mulching and supplementary irrigation on the soil water and heat, and the growth of apple trees. In the experiments, one mulching method (corn straw mulching, SM), two types of drip irrigation, which included above-ground ring drip irrigation (M1) and above-ground two-row drip irrigation (M2), were used. Additionally, three irrigation levels of 100% (W1), 75% (W2), and 50% (W3) of full irrigation (referred to as full, moderate deficit, and severe deficit irrigation, respectively) were used. The results showed that SM significantly increased the soil water content (SWC), especially in the early stage of the growth period. SM significantly reduced and stabilized the soil temperature during the whole growth season, while M1 and M2 had no significant effect on the soil temperature. Both mulching and drip irrigation significantly increased the net photosynthetic rate (Pn) of leaves. Supplementary irrigation had no significant effect on shoot length, but increased shoot diameter. The evapotranspiration of various stages on apple trees was in the following descending order: fruit expansion stage (III), bud development and flowering stage (I), leaf expansion stage (II), and fruit maturing stage (IV). Therefore, SM has the potential to increase apple yields in the Loess Plateau by improving the soil environment and regulating the growth and physiology of apple trees.

Receptor kinases DRUS1 (Dwarf and Runtish Spikelet1) and DRUS2 are orthologues of the renowned Arabidopsis thaliana gene FERONIA, which play redundant roles in rice growth and development. Whether the two duplicated genes perform distinct functions in response to environmental stress is largely unknown. Here, we found that osmotic stress (OS) and ABA increased DRUS1 expression while decreasing DRUS2. When subjected to osmotic stress, the increased DRUS1 in drus2 mutants suppresses the OsIAA repressors, resulting in a robust root system with an increased number of adventitious and lateral roots as well as elongated primary, adventitious, and lateral roots, conferring OS tolerance. In contrast, the decreased DRUS2 in drus1-1 mutants are not sufficient to suppress OsIAA repressors, leading to a feeble root system with fewer adventitious and lateral roots and hindering seminal root growth, rendering OS intolerance. All these findings offer valuable insights into the biological significance of the duplication of two homologous genes in rice, wherein, if one is impaired, the other one is able to continue auxin-signaling-mediated root growth and development to favor resilience to environmental stress, such as water shortage.

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

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

Vacuolar Pi transporters (VPTs) have recently been identified as important regulators of cellular Pi status in Arabidopsis thaliana and Oryza sativa. In the oil crop Brassica napus, BnA09PHT5;1a and BnC09PHT5;1a are two homologs of AtPHT5;1, the vacuolar Pi influx transporter in Arabidopsis. Here, we show that Pi deficiency induces the transcription of both homologs of PHT5;1a genes in B. napus leaves. Brassica PHT5;1a double mutants (DM) had smaller shoots and higher cellular Pi concentrations than wild-type (WT, Westar 10), suggesting the potential role of BnPHT5;1a in modulating cellular Pi status in B. napus. A proteomic analysis was performed to estimate the role of BnPHT5;1a in Pi fluctuation. Results show that Pi deprivation disturbs the abundance of proteins in the physiological processes involved in carbohydrate metabolism, response to stimulus and stress in B. napus, while disruption of BnPHT5;1a genes may exacerbate these processes. Besides, the processes of cell redox homeostasis, lipid metabolic and proton transmembrane transport are supposed to be unbalanced in BnPHT5;1a DM under the -Pi condition. Noteworthy, disruption of BnPHT5;1a genes severely alters the abundance of proteins related to ATP biosynthesis, and proton/inorganic cation transmembrane under normal Pi condition, which might contribute to B. napus growth limitations. Additionally, seven new protein markers of Pi homeostasis are identified in B. napus. Taken together, this study characterizes the important regulatory role of BnPHT5;1a genes as vacuolar Pi influx transporters in Pi homeostasis in B. napus.

Potato black scurf caused by Rhizoctonia solani Kühn is widespread worldwide. The exploration and analysis of the infection mechanism of Rhizoctonia solani Kühn has important scientific significance to enhance the disease resistance of potato and other horticultural crops, and then break the restriction of fungal harm to agricultural production. The physiological and biochemical indexes and the expression levels of related genes were measured at 0, 1, 4, 8 and 16 days (T0, T1, T2, T3, T4) after inoculation with pathogenic bacteria. The results showed that the contents of L-phenylalanine ammonia-lyase (PAL), peroxidase (POD), lignin, total phenols (TP), and flavonoids increased significantly in potato after infection by Rhizoctonia solani Kühn, with the contents of PAL and POD reaching a peak at 8 d and then decreasing, and the contents of lignin and total phenols changing most significantly, reaching the highest levels at day 8 (T3) and day 16 (T4), respectively. During the infestation, the content of eight phenolic compounds increased, and the genes responsible for the lignin synthesis pathway were upregulated. However, in the later stage of infestation, the expression of two genes (PAL PG0031457 and PG2021549, HCT PG0014959, and COMT PG0011266) was down-regulated. In the correlation analysis, gene expression levels of all the genes, except POD (PG0005062), CCoAOMT (PG0018688), and COMT (PG0011266), were found to be positively correlated with the contents of lignin, total phenols, flavonoids, PAL, POD, and eight phenolic substances. Therefore, based on a sound understanding of the occurrence mechanism of Potato black scurf, this experiment analyzed the effect of Rhizoctonia solani Kühn infestation on the content of relevant metabolites in the lignin synthesis pathway as well as gene expression in potatoes, which provides a scientific basis for the prevention and control management of potato black scurf.

Phosphorus (P) is an indispensable macronutrient serving a variety of functions in plants. Inositol pyrophosphates (PP-InsPs) nutrient messengers play vital roles in the signaling of P status and plant growth and development. In this review, we summarize (1) the biosynthetic pathway of PP-InsPs and their regulation by plant P status, (2) the effects of PP-InsPs on the function of the SPX domain-containing proteins in signaling plant P status, (3) the effects of inositol pyrophosphates on auxin signaling through TIR1 and on jasmonate signaling through COI1, and (4) the potential crosstalk between P status signaling and phytohormone signaling in plants mediated by inositol pyrophosphates. It is concluded that the interactions between inositol pyrophosphates and their binding proteins are central to plant P status and developmental responses to different P supply.

Excessive application of chemical fertilizer leads to the problems of low yield and poor quality of potatoes in semi-arid areas. Therefore, the present study aimed to improve potato productivity in a semi-arid region by the partial substitution of organic fertilizers for chemical fertilizers. The field trial was conducted to study the effects of different fertilizer treatments (CK1, no fertilization; CK2, urea 450 kg·ha−1, calcium superphosphate 375 kg·ha−1, potassium sulphate 525 kg·ha−1 (100

Li, Yalin, Yang, Xinyu, Liu, HaiJiang, Wang, Wei, Wang, Chuang, Ding, Guangda, Xu, Fangsen, Wang, Sheliang, Cai, Hongmei, Hammond, John P. ORCID logoORCID: https://orcid.org/0000-0002-6241-3551, White, Philip J, Shabala, Sergey, Yu, Min and Shi, Lei ORCID logoORCID: https://orcid.org/0000-0002-5312-8521 (2022) Local and systemic responses conferring acclimation of Brassica napus roots to low phosphorus conditions. Journal of Experimental Botany, 73 (14). pp. 4753-4777. ISSN 0022-0957 doi: https://doi.org/10.1093/jxb/erac177 Available at https://centaur.reading.ac.uk/105675/

Background Cadmium (Cd) pollution has brought harm to the growth and development of potato. Glutathione (GSH) is an important antioxidant that may play an active role in the response of a potato to Cd stress. However, how GSH influences the effect of Cd on potatoes is unknown. In this study, we investigated the effects of exogenous GSH on the phenylpropanoid biosynthesis pathway and plant hormone signal transduction pathway in potatoes under Cd stress to explore new ideas for how potatoes respond to Cd stress. We cultured 21-day-old 'Atlantic’ plantlets in Murashige and Skoog (MS) medium supplemented with 500 μmol/L CdCl 2 or 500 μmol/L CdCl 2 + 400 μmol/L GSH. We then investigated the activities of key enzymes in the phenylpropanoid biosynthesis pathway, hormone levels, and the expression levels of related genes at different time points. Results Analysis showed that 96 h of treatment with glutathione led to an increase in the expression levels of genes encoding phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD) and peroxidase (POD); an increase in the enzymic activities of PAL, CAD and POD; and an increase in the content of lignin. The content of lignin was positively correlated with the expression levels of several genes (PAL: PG0031457, CAD: PG0005359, POD: PG0011640 and PG0015106). In addition, the levels of Salicylic acid (SA) and Jasmonic acid (JA) increased significantly, the expression levels of the genes encoding transcription factor TGA (PG2023696), pathogenesis-related protein 1 (PR1) (PG0005111), and the transcription inhibitor Aux/IAA (PG0006093) all increased while the expression levels of jasmonate ZIM domain-containing protein (JAZ) (PG0004367), auxin influx carrier (AUX) (PG0006550) and auxin response factor (ARF) (PG0005794) all decreased. We also observed a reduction in the content of IAA. Conclusion Exogenous GSH improved the tolerance of potato, Atlantic cv. to Cd stress by regulating the phenylpropanoid biosynthesis pathway and the plant hormone signal transduction pathway. Graphical Abstract

The aims of this work were to investigate phosphate starvation responses of Brassica napus (B. napus) under heterogeneous phosphate (Pi) supply and the regulatory role of jasmonic acid (JA) in the systemic response to Pi starvation. A split-root system with two separated compartments was employed to mimic heterogeneous Pi distribution in the soil and to examine the effect of heterogeneous Pi supply, and JA or DIECA (JA biosynthesis inhibitor) on growth, root morphology, Pi concentration, Acid phosphatase (APase) activity, nutrition uptake, JA concentration and expression of Pi starvation systemically-induced (PSSI) genes of B. napus. Heterogeneous Pi supply systemically modified root morphology that increased the total root surface area (TRSA), total root volume (TRV), total root length (TRL) and total lateral root number (TLRN) of root with local Pi supply (R +) and decreased them of root with local no Pi supply (R-) when compared to root with homogeneous Pi supply (R + +) and root devoid of Pi (R–), respectively. Anthocyanin, APase activity and JA concentration in shoot and root of B. napus were systemically regulated by heterogeneous Pi supply. In addition, heterogeneous Pi supply significantly promoted nutrient uptake when compared with homogeneous no Pi supply. Root morphology of B. napus was significantly changed by exogenous addition of JA or DIECA in a split-root system. JA enhanced Pi starvation response by inducing expression of PSSI genes in shoots and roots. Our results suggest that JA enhances systemic Pi starvation response of B. napus by regulating root morphology, Pi homeostasis and inducing expression of PSSI genes under heterogeneous Pi supply.

为筛选出适宜在庆阳市种植的小果型西瓜品种,丰富庆阳市日光温室栽培小果型西瓜品种资源.引进了 13 个国内外小果型西瓜品种进行了试种,并对各引进品种的植株形态、果实形态、果肉风味和产量进行了评价.结果表明,13 个参试品种生长特征及果实品质差异显著,其中鼎优美颜中心糖含量最高,达 143.3 g/kg;红小玉的边糖含量最高,为 123.3 g/kg,且中心糖与边糖差最小.综合分析,鼎优美颜与红小玉果型精致小巧、果皮薄、果肉脆甜多汁、纤维含量少,可作为日光温室栽培种在庆阳市种植.

Background Potato ( Solanum tuberosum L.) continuous cropping causes the decrease of tuber yield, deterioration of quality and soil degradation in the semi-arid area. These negative effects can generally be mitigated by legume rotation and mulching. However, little is known about how can mulching and legume rotation alleviate the above damage through altering soil environment. Methods A field experiment was conducted to investigate changes in soil properties and microbial community in response to legume rotation and mulching under six planting patterns: potato continuous cropping without film mulching (PC), potato continuous cropping with film mulching (PCF), potato–broad bean rotation without film mulching (R1), potato–broad bean rotation with film mulching (R1F), potato–pea rotation without film mulching (R2) and potato–pea rotation with film mulching (R2F). Results Compared with the PC, the R1F and R2F had significantly enhanced the contents of alkaline nitrogen (AN), available phosphorus (AP), available potassium (AK), total carbon (TC) and total nitrogen (TN), but reduced soil pH and electrical conductivity (EC). The Shannon index of fungi in R1F and R2 was significantly higher than other treatments. The dominant bacterial and fungal phyla of each treatment was Proteobacteria and Ascomycota. R1, R1F, R2 and R2F enhanced the relative abundance of metabolic fungi and altered key differential microbial species. Soil EC, AN and AK were major factors influencing the soil bacterial and fungal communities. Conclusion Overall, the study demonstrated that potato-broad bean/pea rotation with mulching can be adopted as the preferred cropping systems to alleviate potato continuous cropping obstacles through enhancing soil fertility and regulating soil microbial communities in the semi-arid of Loess Plateau, China. Graphical Abstract