根系对酸胁迫的应激反应及硼调控耐酸机制的研究进展

Root response to acid stress and the mechanism of acid tolerance regulated by boron

过量施用氮肥在提高作物产量的同时加速了土壤酸化进程,近20年间我国农田土壤pH下降了0.42个单位。过多的H+可破坏根系细胞壁结构稳定性,诱导细胞死亡,进而抑制根系伸长,降低其对养分和水分的吸收,限制农产品产量和品质的提高。因此,探究植物对酸胁迫的应激反应机制,对制定缓解酸胁迫措施十分必要。本文综述植株内部调控和耐受酸胁迫的响应,以及硼提高植株耐酸性的机制。通常,植物通过Ca^(2+)和K^(+)通道进行的信号传导可感应介质pH的改变,并同时在基因和蛋白水平进行调控,从而快速响应酸胁迫;近期多项研究表明,硼可调控植物根系有机酸分泌,通过改变细胞壁特性来维持细胞壁结构稳定,并通过刺激乙烯和Ⅲ类过氧化物酶(CIII Prxs)代谢等共同作用缓解植物酸胁迫。目前,对植物酸胁迫的研究逐步深入,但酸胁迫下植物根系代谢产物变化及诱导机制尚不清楚,响应低pH的特定基因尚不明确,仍需进一步研究。

The application of N fertilizer increases crop yield and simultaneously leads to soil acidification. The p H values of farmlands in China have decreased by 0.42 in the past 20 years. H+ directly acts on the root cell wall,induces cell death by destroying the cell wall’s structural stability, and thus inhibits elongation of root and absorption of nutrients and water. Consequently, the growth and development of plants and the yield and quality of agricultural produce are impacted. Therefore, exploring the mechanism of stress response in plants is essential for making the right counter-measurement. This paper summarizes the internal regulation of plants and their response to acid stress and the mechanism of boron in improving plant acid tolerance. The signal transduction of plants through Ca2+ and K+ channels can respond to p H changes and regulate them in gene and protein levels to respond to acid stress quickly. Moreover, recent studies have shown that boron can alleviate plant acid stress. This is achieved by regulating the secretion of organic acids in plant roots, changing cell wall characteristics,maintaining cell wall structure and stability, stimulating ethylene and class III peroxidase(CIII Prxs) metabolism,etc. At present, the research on plant acid stress is gradually deepening, but the changes of plant root metabolites under acid stress and the induction mechanism are not clear, and the specific genes responding to low p H are not clear, so further research is needed.