Mengli Han,Zhao Chen,Genlou Sun,Yuxi Feng,Yuxia Guo,Shiqie Bai,Xuebing Yan
Cadmium (Cd) poses a significant threat to plant growth and the environment. Nano-Fe 3 O 4 is effective in alleviating Cd stress in plants. Elymus nutans Griseb. is an important fodder crop on the Qinghai-Tibetan Plateau (QTP). However, the potential mechanism by which nano-Fe 3 O 4 alleviates Cd stress in E. nutans is not well understood. E. nutans were subjected to single Cd, single nano-Fe 3 O 4 , and co-treatment with nano-Fe 3 O 4 and Cd, and the effects on morphology, Cd uptake, antioxidant enzyme activity, reactive oxygen species (ROS) levels and programmed cell death (PCD) were studied to clarify the regulatory mechanism of nano-Fe 3 O 4 . The results showed that Cd stress significantly decreased the germination percentage and biomass of E. nutans . The photosynthetic pigment content decreased significantly under Cd stress. Cd stress also caused oxidative stress and lipid peroxidation, accumulation of excessive ROS, resulting in PCD, but the effect of nano-Fe 3 O 4 was different. Seed germination, seedling growth, and physiological processes were analyzed to elucidate the regulatory role of nano-Fe 3 O 4 nanoparticles in promoting photosynthesis, reducing Cd accumulation, scavenging ROS, and regulating PCD, to promote seed germination and seedling growth in E. nutans . This report provides a scientific basis for improving the tolerance of Elymus to Cd stress by using nano-Fe 3 O 4 .
Wheat leaf rust (caused byPuccinia triticinaErikss.) is among the major diseases of common wheat. The lack of resistance genes to leaf rust has limited the development of wheat cultivars. Wheat–Agropyron cristatum(A. cristatum) 2P addition line II-9-3 has been shown to provide broad-spectrum immunity to leaf rust. To identify the specificA. cristatumresistance genes and related regulatory pathways in II-9-3, we conducted a comparative transcriptome analysis of inoculated and uninoculated leaves of the resistant addition line II-9-3 and the susceptible cultivar Fukuhokomugi (Fukuho). The results showed that there were 66A. cristatumdifferentially expressed genes (DEGs) and 1389 wheat DEGs in II-9-3 duringP. triticinainfection. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and gene set enrichment analysis (GSEA) revealed that the DEGs of II-9-3 were associated with plant–pathogen interaction, MAPK signaling pathway–plant, plant hormone signal transduction, glutathione metabolism, and phenylpropanoid biosynthesis. Furthermore, many defense-relatedA. cristatumgenes, such as two NLR genes, seven receptor kinase-encoding genes, and four transcription factor-encoding genes, were identified. Our results indicated that the key step of resistance to leaf rust involves, firstly, the gene expression of chromosome 2P upstream of the immune pathway and, secondly, the effect of chromosome 2P on the co-expression of wheat genes in II-9-3. The disease resistance regulatory pathways and related genes in the addition line II-9-3 thus could play a critical role in the effective utilization of innovative resources for leaf rust resistance in wheat breeding.Keywords:wheat;Agropyron cristatum;wheat–A. cristatum2P addition line;resistance gene to leaf rust;gene expression
危险品化学品经营许可证（带存储）