Background: Crop productivity is challenged by abiotic stresses, among which drought stress is the most common.NF-Ygenes, especiallyNF-YAgenes, regulate tolerance to abiotic stress.Results: Soybean NF-Y geneGmNFYA5was identified to have the highest transcript level among all 21NF-YAgenes in soybean (Glycine maxL.) under drought stress. Drought-induced transcript ofGmNFYA5was suppressed by the ABA synthesis inhibitor naproxen (NAP).GmNFYA5transcript was detected in various tissues at vegetative and reproductive growth stages with higher levels in roots and leaves than in other tissues, which was consist with theGmNFYA5promoter: GUS fusion assay. Overexpression ofGmNFYA5in transgenic Arabidopsis plants caused enhanced drought tolerance in seedlings by decreasing stomatal aperture and water loss from leaves. Overexpression and suppression ofGmNFYA5in soybean resulted in increased and decreased drought tolerance, respectively, relative to plants with an empty vector (EV). Transcript levels of ABA-dependent genes (ABI2,ABI3,NCED3,LEA3,RD29A,P5CS1,GmWRKY46,GmNCED2andGmbZIP1) and ABA-independent genes (DREB1A,DREB2A,DREB2B,GmDREB1,GmDREB2andGmDREB3) in transgenic plants overexpressingGmNFYA5were higher than those of wild-type plants under drought stress; suppression ofGmNFYA5transcript produced opposite results. GmNFYA5 probably regulated the transcript abundance ofGmDREB2andGmbZIP1by binding to the promoters in vivo.Conclusions: Our results suggested that overexpression ofGmNFYA5improved drought tolerance in soybean via both ABA-dependent and ABA-independent pathways.
Rice seedling blight, caused by Fusarium oxysporum, significantly affects global rice production levels. Fluoro-substituted benzothiadiazole derivatives (FBT) and chitosan oligosaccharide (COS) are elicitors that can enhance plant resistance to pathogen infection. However, there is a lack of information regarding FBT and COS used as elicitors in rice seedlings blight. Therefore, the aim of this study was to evaluate the effect of FBT and COS treatments on rice seedling blight and elucidate the molecular mechanisms of the two elicitors for inducing resistance using proteomic technique. Results indicated that FBT and COS significantly reduced the disease incidence and index, and relived the root growth inhibition caused by F. oxysporum (p < 0.05). Biochemical analyses demonstrated that these two elicitors effectively enhanced activities of defense enzymes. Moreover, the proteomic results of rice root tissues disclosed more differentially expressed proteins in diterpenoid biosynthesis pathway that were particularly stimulated by two elicitors compared to the other pathways studied, resulting in the accumulation of antimicrobial substance, momilactone. Findings of this study could provide sound theoretical basis for further applications of FBT and COS used as rice elicitors against seedling blight.
In China, rice is one of the most important cereal crops. Rice bacterial brown leaf spot caused by P. s. pv. syringae is among the most damaging rice diseases in the Heilongjiang Province of China and results in substantial yield losses. In this study, a comprehensive analysis of the pathogen, population structure, and genetic diversity within the species was performed. For this purpose, 176 bacterial isolates of P. s. pv. syringae collected from 15 locations were characterized by using biochemical tests such as the LOPAT test, and genetic characterizations such as multilocus sequence analysis (MLSA) and repetitive PCR, using BOX, REP and ERIC primers. Biochemical testing and detection of syrB genes confirm the presence of P. s. pv. syringae, genetic characterization by MLSA and genetic fingerprinting by repetitive PCR confirmed that high genetic heterogeneity exists in the P. s. pv. syringae isolates, and clustering of the tested isolates and reference strains are related with the same genomospecies 1. This work contributes to the physiological classification of the P. s. pv. syringae isolated from Heilongjiang Province, China, and the results present new data concerning the phylogeny and genetic diversity. This type of study about P. s. pv. syringae has been not reported from this region until now.
1 December 2022 in Russian Journal of Plant Physiology
Rice sheath blight is caused by the necrotrophic soil-borne fungus Rhizoctonia solani Kühn. It is one of the most destructive rice disease. Jasmonic acid (JA) plays a vital role in plant defense mechanisms. This study aims to increase the understanding of JA in plant defense mechanisms against R. solani. In this study, we applied four different JA concentrations: 0.01, 0.1, 0.5, and 1 mM. JA application significantly increased the plant resistance against R. solani. The highest relative control of 82.38% was achieved by plants treated with a concentration of 0.1 mM. JA concentration of 0.1 mM is the most suitable treatment and above this concentration, the lesion length started to increase which indicates the reduction of plant resistance. Treatment 0.1 mM JA is further used to investigate defense-related enzymes and the expression of genes. 0.1 mM JA treatment effectively increases the activity of enzymes involved in plant defense mechanisms such as phenylalanine ammonia-lyase (PAL), peroxidase (POD), and β-1,3-glucanase, JA also lowers the malondialdehyde (MDA) content which proves its effectiveness against R. solani. The POX, PAL, and OsPR1b genes are the key marker genes for the plant defense, and the application of JA positively increases the relative expressions of these genes. These results confirm the significance of JA in plant defense mechanisms.
Xanthomonas euvesicatoria has become a serious problem in Physalis pubescens, leading to substantial crop losses. In our previous investigation, we used rapid molecular detection techniques to identify X. euvesicatoria; however, this pathogen’s diversity and population structure remain poorly understood, despite their importance in disease management. To address this knowledge gap, we analyzed the diversity of X. euvesicatoria using BOX-PCR and ERIC-PCR fingerprinting techniques. A total of 103 isolates were collected from 13 counties across Heilongjiang province during the 2018 and 2019 growing seasons. Our findings revealed 635 unique genetic patterns from ERIC-PCR fingerprinting, compared to 360 patterns from BOX-PCR. BOX-PCR analysis identified 12 distinct genotypic clusters, whereas ERIC-PCR identified 14 clusters through unweighted pair group approach with arithmetic average analysis, demonstrating substantial genetic variability. STRUCTURE analysis further identified five distinct genetic clusters in the BOX-PCR data and two in the ERIC-PCR data. The Hailin isolates showed the highest level of diversification compared to other regional isolates. AMOVA results indicated that 85% of the genetic variation in BOX-PCR was attributable to within-population differences, while 78% of ERIC-PCR variation was due to differences across populations. In addition, a Mantel test demonstrated a tenuous correlation between BOX-PCR and ERIC-PCR genetic markers, indicating distinct genetic profiles. This extensive genetic information enhances our understanding of the epidemiology of bacterial leaf spot and its potential therapeutic prospects. These data can provide insights into Xanthomonas strains’ diversity and geographical dissemination.