背景:镉(Cd)污染降低了作物的产量和质量。硒(Se)是一种有益的矿物元素,可保护植物免受氧化损伤,从而提高作物对重金属的耐受性。水稻(Oryzasativa)对硒诱导镉耐性的分子机制尚不清楚。本研究旨在阐明硒(1mg/kg)对减轻水稻幼苗Cd毒性的有益机制。
结果:外源硒显著改善了镉胁迫对水稻幼苗的毒害效应,株高和鲜重分别增加20.53%和34.48%,分别,叶绿素和类胡萝卜素含量分别增加16.68%和15.26%,分别。此外,MDA,·OH,镉胁迫诱导的蛋白质羰基水平降低了47.65%,67.57%,和56.43%,分别。细胞壁代谢,能量循环,水稻幼苗的酶促和非酶促抗氧化系统显著增强。转录组分析表明,关键功能基因psbQ的表达,psbO,psaG,psaD,atpG,和PetH在低浓度硒处理下显著上调,增强了水稻幼苗中光系统I和光系统II的能量代谢过程。同时,LHCA的上调,LHCB家族,和C4H1,PRX,和atp6功能基因提高了植物的光子捕获和重金属离子结合能力。结合蛋白质组分析,功能蛋白OsGSTF1,OsGSTU11,OsG6PDH4,OsDHAB1,CP29和CabE的表达在硒下显著上调,增强水稻幼苗光合作用和抗氧化胁迫机制。同时,调节植物激素信号转导途径。上调IAA的表达反应过程,ABA,和JAZ迅速激活各细胞间的协同作用,共同维持稳态平衡。
结论:我们的结果揭示了硒介导的关键代谢途径的调节过程,功能基因,镉胁迫下大米中的蛋白质。他们提供了对硒介导的植物抗性机制的表达规则和动态响应过程的见解。本研究为农田生态系统和镉污染地区的作物安全提供了理论依据和技术支持。
BACKGROUND: Cadmium (Cd) pollution has declined crop yields and quality. Selenium (Se) is a beneficial mineral element that protects plants from oxidative damage, thereby improving crop tolerance to heavy metals. The molecular mechanism of Se-induced Cd tolerance in rice (Oryza sativa) is not yet understood. This study aimed to elucidate the beneficial mechanism of Se (1 mg/kg) in alleviating Cd toxicity in rice seedlings.
RESULTS: Exogenous selenium addition significantly improved the toxic effect of cadmium stress on rice seedlings, increasing plant height and fresh weight by 20.53% and 34.48%, respectively, and increasing chlorophyll and carotenoid content by 16.68% and 15.26%, respectively. Moreover, the MDA, ·OH, and protein carbonyl levels induced by cadmium stress were reduced by 47.65%, 67.57%, and 56.43%, respectively. Cell wall metabolism, energy cycling, and enzymatic and non-enzymatic antioxidant systems in rice seedlings were significantly enhanced. Transcriptome analysis showed that the expressions of key functional genes psbQ, psbO, psaG, psaD, atpG, and PetH were significantly up-regulated under low-concentration Se treatment, which enhanced the energy metabolism process of photosystem I and photosystem II in rice seedlings. At the same time, the up-regulation of LHCA, LHCB family, and C4H1, PRX, and atp6 functional genes improved the ability of photon capture and heavy metal ion binding in plants. Combined with proteome analysis, the expression of functional proteins OsGSTF1, OsGSTU11, OsG6PDH4, OsDHAB1, CP29, and CabE was significantly up-regulated under Se, which enhanced photosynthesis and anti-oxidative stress mechanism in rice seedlings. At the same time, it regulates the plant hormone signal transduction pathway. It up-regulates the expression response process of IAA, ABA, and JAZ to activate the synergistic effect between each cell rapidly and jointly maintain the homeostasis balance.
CONCLUSIONS: Our results revealed the regulation process of Se-mediated critical metabolic pathways, functional genes, and proteins in rice under cadmium stress. They provided insights into the expression rules and dynamic response process of the Se-mediated plant resistance mechanism. This study provided the theoretical basis and technical support for crop safety in cropland ecosystems and cadmium-contaminated areas.