CaM-binding Protein 60-like G (CBP60g) and Systemic Acquired Resistance Deficient 1 (SARD1) are key immune signalling regulators that redundantly promote salicylic acid (SA) biosynthesis and plant immunity. Pathogen effectors often target these immune nodes to suppress plant defence. However, the role of bacterial effectors in disabling CBP60g and SARD1 to increase plant susceptibility remains unclear. In this study, we show that RipAW, an E3 ligase effector from Ralstonia solanacearum , induces root architecture changes and enhances plant susceptibility to R. solanacearum in Est::RipAW transgenic plants. The constitutively expressed RipAW (C177S) , lacking E3 ligase activity, did not affect root architecture or plant susceptibility, indicating that RipAW's E3 ligase activity is crucial for these phenotypes. Transcriptional profiling of Est::RipAW plants revealed strong up-regulation of CBP60g and SARD1, while the SA signalling pathway remained in a basal state. Transient expression of RipAW and CBP60g in Nicotiana benthamiana showed that RipAW associates with CBP60g and affects its stability. Genetic analysis revealed that loss-of-function mutations in CBP60g and SARD1 increased plant susceptibility to R. solanacearum, but did not enhance RipAW-mediated pathogen growth. Furthermore, growth of the R. solanacearum Δ RipAW null mutant strain was reduced in wild-type plants but restored in cbp60g/sard1 mutant plants, confirming that the promotion of RipAW on bacterial growth is dependent on CBP60g and SARD1. Surprisingly, CBP60g and SARD1 were not involved in R. solanacearum -induced and RipAW-triggered root architecture changes. Overall, our findings demonstrate that RipAW increases plant susceptibility to R. solanacearum via both CBP60g/SARD1-dependent and -independent pathways.

AbstractDiverse pathogen effectors convergently target conserved components in plant immunity guarded by intracellular nucleotide‐binding domain leucine‐rich repeat receptors (NLRs) and activate effector‐triggered immunity (ETI), often causing cell death. Little is known of the differences underlying ETI in different plants triggered by the same effector. In this study, we demonstrated that effector RipAW triggers ETI on Nicotiana benthamiana and Nicotiana tabacum. Both the first 107 amino acids (N1‐107) and RipAW E3‐ligase activity are required but not sufficient for triggering ETI on N. benthamiana. However, on N. tabacum, the N1‐107 fragment is essential and sufficient for inducing cell death. The first 60 amino acids of the protein are not essential for RipAW‐triggered cell death on either N. benthamiana or N. tabacum. Furthermore, simultaneous mutation of both R75 and R78 disrupts RipAW‐triggered ETI on N. tabacum, but not on N. benthamiana. In addition, N. tabacum recognizes more RipAW orthologs than N. benthamiana. These data showcase the commonalities and specificities of RipAW‐activated ETI in two evolutionally related species, suggesting Nicotiana species have acquired different abilities to perceive RipAW and activate plant defences during plant–pathogen co‐evolution.

In order to investigate the influence of X-ray irradiation dose on the germination and storage quality of coloured potatoes, this study took the coloured potatoes Yellow Rose 3, Purple Rose 3, Red Rose 5 and common potatoes as test materials, and treated them with 5 MeV electron-beam rotary target X-rays at 0, 100, 300 and 500 Gy. The treated potatoes were stored at room temperature (20±2) ℃ with a relative humidity of 80%~90%. In order to study the influence of X-ray irradiation on the appearance, nutritional quality and fresh-keeping effects of potatoes, parameter changes of germination rate, weight loss rate, hardness, VC content, dry matter content and respiration intensity during the storage period were analyzed. The results showed that X-ray irradiation treatment reduced the respiratory intensity of potatoes in the mid to late storage period and decreased the weight loss, hardness decline and loss of VC content during storage. Compared with control group, 100 Gy irradiation treated Yellow Rose 3, Purple Rose 3, Red Rose 5 and common potatoes reduced the weight loss rate by 12.76%, 5.31%, 6.05% and 1.43%, respectively, the degree of decrease in hardness at the end of the storage period compared with the beginning of storage period was reduced by 12.98%, 6.40%, 8.34% and 7.13%, respectively, and the rate of loss of VC content was reduced by 17.71%, 22.80%, 13.52% and 14.65%, respectively. Four varieties of potatoes did not sprout even after storage for more than 240 days after receiving different doses of X-rays. A low dose of 100 Gy of X-ray irradiation treatment could achieve an optimal sprout inhibition effect. Moreover, it delayed weight loss and hardness decline more effectively than 300 and 500 Gy. This dose could be recommended as the dose for irradiation preservation of coloured and ordinary potatoes in industrial applications. This research provides a theoretical basis and technical guidance for the application of X-ray irradiation technology in the storage and preservation of coloured potatoes.

Cytokinin signalling plays both positive and negative roles in plant resistance to pathogens. It is not clear whether the role of cytokinin changes at the different stages of pathogen infection. Arabidopsis thaliana sequentially exhibits distinct root morphological symptoms during Ralstonia solanacearum infection, which offers a good system to investigate function of cytokinin in the whole pathogen infection process. Using this system, we found increase of cytokinin signalling by Lonely Guy 2 (LOG2) overexpression or depletion of type-A Arabidopsis Response Regulators (ARRs), negative regulators of cytokinin signalling pathway, promoted cell death, wilting symptom and bacterial growth, but attenuated primary root growth inhibition and lateral root formation. The decrease of cytokinin signalling by mutation on Isopentenyl Transferases (IPTs) inhibited root hair formation, cell death, wilting symptom and bacterial colonisation. Application of different concentration of exogenesis 6-benzylaminopurine (6-BA) showed first promoted, then decreased root hair formation. Moreover, application of 6-BA accelerated cell death but suppressed lateral root formation and primary root growth inhibition. The diverse roles of cytokinin in these different root disease phenotypes suggested function of cytokinin during plant responses to R. solanacearum is cell type-specific, which provides new insights on roles of cytokinin signalling in regulation on plant-pathogen interactions.

4-coumarate: CoA ligase (4CL) is not only involved in the biosynthetic processes of flavonoids and lignin in plants but is also closely related to plant tolerance to abiotic stress. UV irradiation can activate the expression of 4CL genes in plants, and the expression of 4CL genes changed significantly in response to different phytohormone treatments. Although the 4CL gene has been cloned in potatoes, there have been fewer related studies of the 4CL gene family on the potato genome-wide scale. In this study, a total of 10 potato 4CL genes were identified in the potato whole genome. Through multiple sequence alignment, phylogenetic analysis as well as gene structure analysis indicated that the potato 4CL gene family could be divided into two subgroups. Combined with promoter cis-acting element analysis, transcriptome data, and RT-qPCR results indicated that potato 4CL gene family was involved in potato response to white light, UV irradiation, ABA treatment, MeJA treatment, and PEG simulated drought stress. Abiotic stresses such as UV, ABA, MeJA, and PEG could promote the up-regulated expression of St4CL6 and St4CL8 but inhibits the expression of St4CL5. The above results will increase our understanding of the evolution and expression regulation of the potato 4CL gene family and provide reference value for further research on the molecular biological mechanism of 4CL participating in response to diverse environmental signals in potatoes.

Background Anthocyanins, which account for color variation and remove reactive oxygen species, are widely synthesized in plant tissues and organs. Using targeted metabolomics and nanopore full-length transcriptomics, including differential gene expression analysis, we aimed to reveal potato leaf anthocyanin biosynthetic pathways in different colored potato varieties. Results Metabolomics analysis revealed 17 anthocyanins. Their levels varied significantly between the different colored varieties, explaining the leaf color differences. The leaves of the Purple Rose2 (PurpleR2) variety contained more petunidin 3-O-glucoside and malvidin 3-O-glucoside than the leaves of other varieties, whereas leaves of Red Rose3 (RedR3) contained more pelargonidin 3-O-glucoside than the leaves of other varieties. In total, 114 genes with significantly different expression were identified in the leaves of the three potato varieties. These included structural anthocyanin synthesis–regulating genes such as F3H , CHS , CHI , DFR , and anthocyanidin synthase and transcription factors belonging to multiple families such as C3H, MYB, ERF, NAC, bHLH, and WRKY. We selected an MYB family transcription factor to construct overexpression tobacco plants; overexpression of this factor promoted anthocyanin accumulation, turning the leaves purple and increasing their malvidin 3-o-glucoside and petunidin 3-o-glucoside content. Conclusions This study elucidates the effects of anthocyanin-related metabolites on potato leaves and identifies anthocyanin metabolic network candidate genes.

Phenylalanine ammonia-lyase is one of the most widely studied enzymes in the plant kingdom. It is a crucial pathway from primary metabolism to significant secondary phenylpropanoid metabolism in plants, and plays an essential role in plant growth, development, and stress defense. Although PAL has been studied in many actual plants, only one report has been reported on potato, one of the five primary staple foods in the world. In this study, 14 StPAL genes were identified in potato for the first time using a genome-wide bioinformatics analysis, and the expression patterns of these genes were further investigated using qRT-PCR. The results showed that the expressions of StPAL1, StPAL6, StPAL8, StPAL12, and StPAL13 were significantly up-regulated under drought and high temperature stress, indicating that they may be involved in the stress defense of potato against high temperature and drought. The expressions of StPAL1, StPAL2, and StPAL6 were significantly up-regulated after MeJa hormone treatment, indicating that these genes are involved in potato chemical defense mechanisms. These three stresses significantly inhibited the expression of StPAL7, StPAL10, and StPAL11, again proving that PAL is a multifunctional gene family, which may give plants resistance to multiple and different stresses. In the future, people may improve critical agronomic traits of crops by introducing other PAL genes. This study aims to deepen the understanding of the versatility of the PAL gene family and provide a valuable reference for further genetic improvement of the potato.

Ziziphi Spinosae Semen (the dried seeds of Ziziphus jujuba Mill. var. spinosa, Rhamnaceae) is a well-known traditional Chinese medicine (TCM) with high edible and pharmaceutical value. It contains abundant phytochemicals and possesses multiple biological activities. Phytochemicals include saponins, flavonoids, alkaloids, fatty acids, and others. Among them, saponins and flavonoids are considered to be the characteristic components of Ziziphi Spinosae Semen. Both crude extracts and isolated compounds exhibit excellent bioactivities, including sedative-hypnosis, anti-anxiety, antidepressant, anticancer, anti-inflammatory, anti-Alzheimer's disease (AD), and others. Its potential therapeutic effect on AD has received increasing attention in recent years. Updated reviews to summarize the current research progress and deficiencies are urgently needed. This review summarized its pharmacological activity, quality control, and application. In addition, the existing problems and future development directions are also discussed. PRACTICAL APPLICATIONS: Ziziphi Spinosae Semen is a vital traditional Chinese medicine that has a varied therapeutic effects. It is also added to food products due to its nontoxic properties. Reliable pharmacological studies have confirmed that it has multiple pharmacological activities. Particularly, its potential therapeutic effect on Alzheimer's disease (AD) has received significant attention, which makes Ziziphi Spinosae Semen an important potential candidate in the research of new drugs and health foods for the prevention of AD. This paper reviews the recent studies on Ziziphi Spinosae Semen in the treatment of AD. In addition, the quality control methods and practical applications are systematically summarized. It may provide essential guidance for the further utilization of Ziziphi Spinosae Semen in food and pharmaceutical industry.

Pear production was seriously threatened by Valsa canker, a notorious disease caused by the necrotrophic fungus Valsa pyri (Vp), but the molecular mechanism is elusive. Currently, the dynamic gene expression profiles of main susceptible variety 'Zaosu' (Pyrus bretschneideri Rehd.) in response to Vp were investigated using RNA sequencing (RNA-seq). In total, 286, 1912, and 6321 differentially expressed genes (DEGs) were detected from the infected phloem tissues at 1, 2, and 4 days after infection, respectively. Functional terms "Stress biotic", "Signaling. receptor kinase", and "Plant hormone signal transduction" were significantly enriched. DEGs associated with Ethylene, Chitinase, Glycosyl hydrolase, and receptor-like kinase (RLK) subfamilies LysM and WAK_LRK10L-1 were mainly up-regulated and contributed to induction of the immune responses in 'Zaosu'. On the contrary, DEGs involved in auxin and brassinosteroid signals, receptor-like protein, nucleotide-binding leucine-rich repeat (NB-LRR), and RLK subfamilies CrRLK1L-1, LRR-III, LRR-VII, and LRR-XII are mainly down-regulated, which are the reasons why 'Zaosu' fails to prevent Vp invasion. Our results highlight new insights into pear responses against Vp and perhaps other necrotrophs.

以LysM(Pfam:PF01476)和Pkinase(Pfam:PF00069)保守域全蛋白序列为种子序列,在苹果属(Malus spp.)及梨属(Pyrus spp.)植物基因组范围内鉴定了4个物种[苹果(M.pumila)'嘎啦'、山荆子(M.baccata)、杜梨(P.betulifolia)、白梨(Pyrus bretschneideri)'玉露香']的LysM-RLK家族成员,并对该家族成员的生物信息学和响应腐烂病菌(Valsa canker)信号的表达模式进行了分析.共获得37个LysM-RLK家族成员,主要定位于质膜;进化分析发现以上4个物种及拟南芥(Arabidopsis thaliana)和水稻(Oryza sativa)的Ly-sM-RLK分为2个亚组;基因重复分析发现苹果和梨中都存在全基因组重复或片段重复现象,但仅苹果'嘎啦'中存在基因串联重复现象;该基因家族成员的启动子区域存在多个响应植物激素或逆境胁迫信号的元件;在腐烂病菌侵染后31个LysM-RLK成员存在差异表达,其中成员MD04G1238900、MD04G1238700、Chr9.g46389和Chr4.g40822(GDR数据库)表达量显著上调,可作为进一步开展抗病研究和功能分析的候选基因.

Auxin is the only plant hormone that exhibits transport polarity mediated by three families: auxin resistant (AUX) 1/like AUX1 (LAX) influx carriers, pin-formed (PIN) efflux carriers, and ATP-binding cassette B (ABCB) influx/efflux carriers. Extensive studies about the biological functions of auxin transporter genes have been reported in model plants. Information regarding these genes in potato remains scarce. Here, we conducted a comprehensive analysis of auxin transporter gene families in potato to examine genomic distributions, phylogeny, co-expression analysis, gene structure and subcellular localization, and expression profiling using bioinformatics tools and qRT-PCR analysis. From these analyses, 5 StLAXs, 10 StPINs, and 22 StABCBs were identified in the potato genome and distributed in 10 of 18 gene modules correlating to the development of various tissues. Transient expression experiments indicated that three representative auxin transporters showed plasma membrane localizations. The responsiveness to auxin and auxin transport inhibitors implied their possible roles in mediating intercellular auxin homoeostasis and redistribution. The differential expression under abscisic acid and abiotic stresses indicated their specific adaptive mechanisms regulating tolerance to environmental stimuli. A large number of auxin-responsive and stress-related cis-elements within their promoters could account for their responsiveness to diverse stresses. Our study aimed to understand the biological significance of potato auxin transporters in hormone signaling and tolerance to environmental stresses.

KEY MESSAGE:In Rosaceae, tandem duplication caused the drastic expansion of CNGC gene family Group I. The members MdCN11 and MdCN19 negatively regulate Valsa canker resistance. Apple (Malus domestica) and pear (Pyrus bretschneideri and P. communis) are important fruit crops in Rosaceae family but are suffering from threats of Valsa canker. Cyclic nucleotide-gated ion channels (CNGCs) take crucial roles in plant immune responses. In the present study, a total of 355 CNGCs was identified from 8 Rosaceae plants. Based on phylogenetic analysis, 540 CNGCs from 18 plants (8 in Rosaceae and 10 others) could be divided into four groups. Group I was greatly expanded in Rosaceae resulted from tandem duplications. A large number of cis-acting regulatory elements (cis-elements) responsive to signals from multiple stresses and hormones were identified in the promoter regions of CNGCs in Malus spp. and Pyrus spp. Expressions of most Group I members were obviously up-regulated in Valsa canker susceptible varieties but not in the resistant ones. Furthermore, overexpression of the MdCN11 and MdCN19 in both apple fruits and 'Duli' (P. betulifolia) suspension cells compromised Valsa canker resistance. Overexpression of MdCN11 induced expression of hypersensitive response (HR)-related genes. In conclusion, tandem duplication resulted in a drastic expansion of CNGC Group I members in Rosaceae. Among these, MdCN11 and MdCN19 negatively regulate the Valsa canker resistance via inducting HR.

同源异形框(homeobox,HB)基因在植物的生长和发育过程中起着重要的作用,许多植物的HB基因已被鉴定.但是,马铃薯(Solanum tuberosum)HB基因的完整鉴定和分类仍然未见报道.本研究在马铃薯中共鉴定了35个同源框基因,利用多种生物信息学方法分析了其理化性质、系统进化关系、染色体定位、基因和蛋白结构、潜在功能,并通过qRT-PCR技术对马铃薯HB家族基因组织特异性表达模式进行了研究.根据邻接系统发育树和结构域组成,35个马铃薯HB基因被分为6个亚家族.对外显子、内含子结构和保守模体的分析有助于进一步了解这些基因间的进化关系.马铃薯和拟南芥(Arabidopsis thaliana)以及番茄(S.lycopersicum)基因组共线性分析表明这些基因存在潜在的功能相关性.所有马铃薯HB基因都分布在12条染色体上,通过RNA测序(RNA sequencing,RNA-Seq)和qRT-PCR分析,马铃薯HB基因StBEL35(S.tuberosum bell-type homeobox 35)、StKNOX1(S.tuberosum KNOTTED1-like homeobox 1)和StKNOX9在贮藏器官(匍匐茎和块茎)上表现出相对较高的表达水平,且大都在成熟块茎中有更高的表达量,表明其可能在块茎发育的后期起作用.结合之前的研究,StBEL35、StKNOX1与StKNOX9基因可能参与赤霉素生物合成,从而影响块茎的形成,本研究有助于这些基因的功能分析,并为进一步分析马铃薯HB基因家族的分子功能提供全面的信息,为马铃薯分子育种提供理论基础.

该研究以转彩色马铃薯StAN1基因烟草为材料、野生型烟草(WT)为对照,测定分析转StAN1基因烟草在种子萌发期、幼苗期和苗期对干旱(甘露醇)处理的耐受情况,并对苗期旱热共同胁迫的耐受情况进行测定分析,以探讨彩色马铃薯StAN1基因的功能,为耐旱彩色马铃薯育种提供新路径.结果显示:(1)转StAN1基因烟草鉴定显示,阳性率为82.6％,且转基因烟草的叶片明显变紫,花青素含量极显著高于野生型烟草.(2)在培养基甘露醇浓度为150 mmol/L时,点播在培养基上的转基因烟草种子第5天时的萌发率达到了7％,是野生型烟草萌发率的2.3倍.(3)在甘露醇浓度为0和100 mmol/L的培养基上竖直培养时,转基因烟草的根长分别是野生型烟草的1.46和1.30倍,根长比野生型烟草显著增长.(4)在干旱胁迫下,转基因烟草幼苗叶片中的脯氨酸含量以及超氧化物歧化酶活性均显著高于野生型烟草,丙二醛含量均显著低于野生型烟草.(5)转基因烟草LEA基因和ERF基因在干旱和旱热处理中的相对表达量均高于野生型烟草.研究表明,StAN1基因在提高植物花青素含量的同时也提高了植物的耐旱性.

Biofilms and intracellular bacteria often cause a series of overwhelming public health issues due to their strong drug resistance. Hence, chitosan nanoparticles (CS NPs), phosphatidylcholine and gentamidn were used to synthesize a novel nanodrug delivery system (GPC NPs). Dynamic light scattering (DLS) demonstrated that the surface zeta-potential of GPC NPs was -19.5 mV. The morphology of GPC NPs was observed by scanning electron microscopy (SEM). The gentamicin adsorption and release behaviors of GPC NPs were also investigated. The GPC NPs could effectively damage and remove the biofilm formed by pathogens through permeation of the antibiotic into the biofilm. In addition, the nanoparticles were readily engulfed by macrophages which facilitated the killing of intracellular bacteria and had neglectable cytotoxicity. Our study indicated that GPC NPs could be used as a promising nanoantibacterial agent against biofilms and intracellular bacteria. (C) 2020 Published by Elsevier B.V.

Additional file 1. Select information about all CBF/DREB1 proteins. a: The protein length, chromosomal location, gene name, and group of each gene. b: Duplication events.

Heat shock protein 90 genes/proteins (Hsp90s) are related to the stress resistance found in various plant species. These proteins affect the growth and development of plants and have important effects on the plants under various stresses (cold, drought and salt) in the environment. In this study, we identified 334 Hsp90s from 43 plant species, and Hsp90s were found in all species. Phylogenetic tree and conserved domain database analysis of all Hsp90s showed three independent clades. The analysis of motifs, gene duplication events, and the expression data from PGSC website revealed the gene structures, evolution relationships, and expression patterns of the Hsp90s. In addition, analysis of the transcript levels of the 7 Hsp90s in potato (Solanum tuberosum) under low temperature and high temperature stresses showed that these genes were related to the temperature stresses. Especially StHsp90.2 and StHsp90.4, under high or low temperature conditions, the expression levels in leaves, stems, or roots were significantly up-regulated. Our findings revealed the evolution of the Hsp90s, which had guiding significance for further researching the precise functions of the Hsp90s.

Background: The sequencing potato DM1-3-516-R44 played an irreplaceable role in the study of gene function. So far, no one research the transformation system about DM. Therefore, our experiment was studied from three aspects: plant regeneration system, optimization of agrobacterium infection conditions and the effect of hygromycin on DM.Results: A relatively suitable method for genetic transformation of DM was obtained: 1) The stem callus induction medium was MS + IAA 0.5 mg/L + 6-BA 2.0 mg/L, the leaf callus induction medium was MS + NAA 1.0mg/L + 6-BA 0.5mg/L and the shoot differentiation medium was MS + 6-BA 3.0 mg/L + ZT 0.5 mg/L. 2) The specific transformation condition was the agrobacterium concentration kept the OD600 = 0.3, and co-culture time consisted 3 days in the dark. The hygromycin concentration chose 8 mg/L to screen the transgenic plants. 3) Using hygromycin to screen about 100 transgenic shoots, 75 shoots were obtained and 53 strains were identified had target stripe by PCR technology.Conclusion: The efficiency of the transformation system we created was over 50%. It provided a good basis for the study of potato gene function.

PHT1 (phosphate transporter 1) family genes play important roles in regulating plant growth and responding to stress. However, there has been little research on the role of the PHT1 family in potatoes. In this study, using molecular and bioinformatic approaches, 8 PHT1 family genes were identified from the potato genome. StPHT1;7 was highly expressed in the whole potato plants. The overexpression and silence vectors of StPHT1;7 were constructed and transformed into the potato cultivar Desiree. Consequently, StPHT1;7 overexpression (with a relative expression 2–7-fold that in the control) and silence lines (with a relative expression of 0.3%–1% that in the control) were obtained. Their growth vigor was ranked in the order overexpression line > wild type > silence line. In the absence of phosphorus, the root length of the overexpression line was approximately 2.6 times that of the wild type, while the root length of the silence line was approximately 0.6 times that of the wild type. Furthermore, their tolerance to drought stress was ranked as wild type > overexpression line > silence line. These results suggest that StPHT1;7 affects growth and stress tolerance in potato plants.

Background: Amino acid transporters mediated the transport of various amino acids in plants, which were essential for plant growth and development. ATFs (the amino acid transporter family) was one of amino acid transporters in plants and AAPs (amino acid permease) subfamily belongs to the ATFs family. Results: In this research, eight AAP genes were identified in the potato and divided into two subgroups. The first subgroup is the StAAP gene containing six microporous transport channels (Pore-lining), and the second subgroup are the StAAP gene containing seven microporous transport channels. The subcellular location and overexpression vectors were built by StAAP1 and StAAP8 . The results indicated these two genes were localized on the cell membrane. Observing the phenotype of the transgenic plants, StAAP1 and StAAP8 promoted the growth of leaves, StAAP1 changed the shape of tubers and enhanced their weight and StAAP8 was no significant influence in tubers but decreased the weight a little. Conclusions: In this study, the expression pattern showed StAAP8 might regulate the transport of amino acids in potato roots and affect the osmotic potential of potato root cells. Thereby, the tolerance of plants to abiotic stress and StAAP1 and StAAP8 promote the amino acid transport into leaves and StAAP1 had effected on tuber development and StAAP8 might resist the weight of tubers.