The NPR1 (nonexpressor of pathogenesis-related genes 1) gene is an activator of the systemic acquisition of resistance (SAR) in plants and is one of the central factors in their response to pathogenic bacterial infestation, playing an important role in plant disease resistance. Potato (Solanum tuberosum) is a crucial non-grain crop that has been extensively studied. However, the identification and analysis of the NPR1-like gene within potato have not been understood well. In this study, a total of six NPR1-like proteins were identified in potato, and phylogenetic analysis showed that the six NPR1-like proteins in Solanum tuberosum could be divided into three major groups with NPR1-related proteins from Arabidopsis thaliana and other plants. Analysis of the exon–intron patterns and protein domains of the six NPR1-like genes from potato showed that the exon–intron patterns and protein domains of the NPR1-like genes belonging to the same Arabidopsis thaliana subfamily were similar. By performing quantitative real-time PCR (qRT-PCR) analysis, we found that six NPR1-like proteins have different expression patterns in different potato tissues. In addition, the expression of three StNPR1 genes was significantly downregulated after being infected by Ralstonia solanacearum (RS), while the difference in the expression of StNPR2/3 was insignificant. We also established potato StNPR1 overexpression lines that showed a significantly increased resistance to R. solanacearum and elevated activities of chitinase, β-1,3-glucanase, and phenylalanine deaminase. Increased peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities, as well as decreased hydrogen peroxide, regulated the dynamic balance of reactive oxygen species (ROS) in the StNPR1 overexpression lines. The transgenic plants activated the expression of the genes associated with the Salicylic acid (SA) defense response but suppressed the expression of the genes associated with Jasmonic acid (JA) signaling. This resulted in resistance to Ralstonia solanacearum.

As a vicious invasive plant, Cyclachaena xanthiifolia has caused severe ecological disruption and significant reductions in crop yield, necessitating urgent control measures. However, the underlying mechanisms of its allelopathic invasion remain unclear, representing the primary bottleneck in current management strategies. In this study, we used metabolomic and transcriptomic analyses to evaluate the differences in allelopathy and related physiological and biochemical indices among different extract fractions of C.xanthiifolia, and to investigate how the allelopathy of C.xanthiifolia inhibits seed germination and seedling growth by altering metabolic pathways. GC-MS results identified several compounds with allelopathic potential, including fatty acids, terpenes, esters, alkanes, and aldehydes. Among them, n-butanol phase extract (NE) treatment significantly inhibited the germination and water absorption of mustard (Brassica juncea) seeds, changed the balance of the endogenous hormones abscisic acid (ABA) and gibberellins (GA) in seeds, destroyed the antioxidant enzyme system, and caused plasma membrane damage. Moreover, transcriptomic and broadly targeted metabolomic analyses showed that NE treatment interfered with primary metabolism, significantly enriched the carotenoid biosynthetic pathway, and led to a significant accumulation of ABA. The quantitative real-time PCR (qRT-PCR) results showed that the expression levels of 7 key genes involved in ABA biosynthesis and metabolic pathways were relatively high. The results showed that C.xanthiifolia may exert its allelopathic effects by disrupting the antioxidant enzyme system and interfering with primary metabolism and hormone signalling, and that the modulation of the ABA signalling pathway appears to play a key role.

Potato is an important food crop that occupies lesser area but has greater production than rice and wheat. However, potato production is affected by numerous biotic and abiotic stresses, among which Fusarium dry rot is a disease that has significant effect on potato production, storage, and processing. However, the role of DNA methylation in regulating potato response to Fusarium toxin deoxynivalenol (DON) stress is still not fully understood. In this study, we performed DNA methylome and transcriptome analyses of potato tubers treated with five concentrations of DON. The global DNA methylation levels in potato tubers treated with different concentrations of DON showed significant changes relative to those in the control. In particular, the 20 ng/ml treatment showed the largest decrease in all three contexts of methylation levels, especially CHH contexts in transposon regions. The differentially methylated region (DMR)-associated differentially expressed genes (DEGs) were significantly enriched in resistance-related metabolic pathways, indicating that DNA methylation plays an essential role in potato response to DON stress. Furthermore, we examined lesions on potato tubers infested with Fusarium after treatment. Furthermore, the potato tubers treated with 5 and 35 ng/ml DON had lesions of significantly smaller diameters than those of the control, indicating that DON stress may induce resistance. We speculate that this may be related to epigenetic memory created after DNA methylation changes. The detailed DNA methylome and transcriptome profiles suggest that DNA methylation plays a vital role in potato disease resistance and has great potential for enhancing potato dry rot resistance.

Universal stress proteins (USPs) play an important regulatory role in responses to abiotic stress. Most of the research related to USPs so far has been conducted on plant models such as Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa L.), and cotton (Gossypium hirsutum L.). The potato (Solanum tuberosum L.) is one of the four major food crops in the world. The potato is susceptible to mechanical damage and infection by pathogenic fungi during transport and storage. Deoxynivalenol (DON) released by Fusarium can seriously degrade the quality of potatoes. As a result, it is of great significance to study the expression pattern of the potato StUSP gene family under abiotic stress conditions. In this study, a total of 108 USP genes were identified from the genome of the Atlantic potato, divided into four subgroups. Based on their genetic structure, the physical and chemical properties of their proteins and other aspects of their biological characteristics are comprehensively analyzed. Collinear analysis showed that the homologous genes of StUSPs and four other representative species (Solanum lycopersicum, Arabidopsis, Oryza sativa L., and Nicotiana attenuata) were highly conserved. The cis-regulatory elements of the StUSPs promoter are involved in plant hormones, environmental stress, mechanical damage, and light response. RNA-seq analysis showed that there are differences in the expression patterns of members of each subgroup under different abiotic stresses. A Weighted Gene Coexpression Network Analysis (WGCNA) of the central gene showed that the differential coexpression gene is mainly involved in the plant–pathogen response process, plant hormone signal transduction, and the biosynthesis process of secondary metabolites. Through qRT-PCR analysis, it was confirmed that StUSP13, StUSP14, StUSP15, and StUSP41 may be important candidate genes involved in the response to adversity stress in potatoes. The results of this study provide a basis for further research on the functional analysis of StUSPs in the response of potatoes to adversity stress.

As a type of cell-wall-relaxing protein that is widely present in plants, expansins have been shown to actively participate in the regulation of plant growth and responses to environmental stress. Wild soybeans have long existed in the wild environment and possess abundant resistance gene resources, which hold significant value for the improvement of cultivated soybean germplasm. In our previous study, we found that the wild soybean expansin gene GsEXLB14 is specifically transcribed in roots, and its transcription level significantly increases under salt and drought stress. To further identify the function of GsEXLB14, in this study, we cloned the CDS sequence of this gene. The transcription pattern of GsEXLB14 in the roots of wild soybean under salt and drought stress was analyzed by qRT-PCR. Using an Agrobacterium rhizogenes-mediated genetic transformation, we obtained soybean hairy roots overexpressing GsEXLB14. Under 150 mM NaCl- and 100 mM mannitol-simulated drought stress, the relative growth values of the number, length, and weight of transgenic soybean hairy roots were significantly higher than those of the control group. We obtained the transcriptomes of transgenic and wild-type soybean hairy roots under normal growth conditions and under salt and drought stress through RNA sequencing. A transcriptomic analysis showed that the transcription of genes encoding expansins (EXPB family), peroxidase, H⁺-transporting ATPase, and other genes was significantly upregulated in transgenic hairy roots under salt stress. Under drought stress, the transcription of expansin (EXPB/LB family) genes increased in transgenic hairy roots. In addition, the transcription of genes encoding peroxidases, calcium/calmodulin-dependent protein kinases, and dehydration-responsive proteins increased significantly. The results of qRT-PCR also confirmed that the transcription pattern of the above genes was consistent with the transcriptome. The differences in the transcript levels of the above genes may be the potential reason for the strong tolerance of soybean hairy roots overexpressing the GsEXLB14 gene under salt and drought stress. In conclusion, the expansin GsEXLB14 can be used as a valuable candidate gene for the molecular breeding of soybeans.

Expansin is a cell wall relaxant protein that is common in plants and directly or indirectly participates in the whole process of plant root growth, development and morphogenesis. A well-developed root system helps plants to better absorb water and nutrients from the soil while effectively assisting them in resisting osmotic stress, such as salt stress. In this study, we observed and quantified the morphology of the roots of Arabidopsis overexpressing the TaEXPAs gene obtained by the research group in the early stage of development. We combined the bioinformatics analysis results relating to EXPA genes in five plants and identified TaEXPA7-B, a member of the EXPA family closely related to root development in winter wheat. Subcellular localization analysis of the TaEXPA7-B protein showed that it is located in the plant cell wall. In this study, the TaEXPA7-B gene was overexpressed in rice. The results showed that plant height, root length and the number of lateral roots of rice overexpressing the TaEXPA7-B gene were significantly higher than those of the wild type, and the expression of the TaEXPA7-B gene significantly promoted the growth of lateral root primordium and cortical cells. The plants were treated with 250 mM NaCl solution to simulate salt stress. The results showed that the accumulation of osmotic regulators, cell wall-related substances and the antioxidant enzyme activities of the overexpressed plants were higher than those of the wild type, and they had better salt tolerance. This paper discusses the effects of winter wheat expansins in plant root development and salt stress tolerance and provides a theoretical basis and relevant reference for screening high-quality expansin regulating root development and salt stress resistance in winter wheat and its application in crop molecular breeding.