International Institute of Tropical Agriculture (IITA), Mikocheni B, Dar es Salaam 34441, Tanzania.
Int J Mol Sci. 2019 Apr 10;20(7):1769. doi: 10.3390/ijms20071769.
Drought conditions marked by water deficit impede plant growth thus causing recurrent decline in agricultural productivity. Presently, research efforts are focussed towards harnessing the potential of microbes to enhance crop production during drought. Microbial communities, such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) buddy up with plants to boost crop productivity during drought via microbial induced systemic tolerance (MIST). The present review summarizes MIST mechanisms during drought comprised of modulation in phytohormonal profiles, sturdy antioxidant defence, osmotic grapnel, bacterial exopolysaccharides (EPS) or AMF glomalin production, volatile organic compounds (VOCs), expression of fungal aquaporins and stress responsive genes, which alters various physiological processes such as hydraulic conductance, transpiration rate, stomatal conductivity and photosynthesis in host plants. Molecular studies have revealed microbial induced differential expression of various genes such as (), (ABA-responsive gene) in , (regulates energy and carbohydrate metabolism), (protein kinase), (stress responsive pathway), , and (chaperones in ABA signalling) in treated rice, , (encoding potassium channels) in Lycium, and (IAA biosynthesis) in AMF inoculated , , , , , and (polyamine biosynthesis) in PGPR inoculated , 14-3-3 genes (- genes in ABA signalling pathways) in AMF treated , , (ethylene biosynthesis), jasmonate gene in chick pea, (SA regulated gene), (JA marker genes) and (ethylene-response gene) in treated plants. Moreover, the key role of miRNAs in MIST has also been recorded in RA treated chick pea plants.
干旱条件下的水分亏缺会阻碍植物生长，从而导致农业生产力的反复下降。目前，研究工作的重点是利用微生物的潜力来提高作物在干旱条件下的生产力。微生物群落，如丛枝菌根真菌（AMF）和植物促生根际细菌（PGPR），通过微生物诱导的系统耐受性（MIST）与植物协同作用，在干旱条件下提高作物生产力。本综述总结了干旱条件下的 MIST 机制，包括植物激素谱的调节、坚固的抗氧化防御、渗透索、细菌胞外多糖（EPS）或 AMF 胶蛋白的产生、挥发性有机化合物（VOCs）、真菌水通道蛋白和应激响应基因的表达，这些机制改变了宿主植物的各种生理过程，如水力传导率、蒸腾速率、气孔导度和光合作用。分子研究表明，微生物诱导了各种基因的差异表达，如在水稻中处理的 （）、（ABA 响应基因）、（调节能量和碳水化合物代谢）、（蛋白激酶）、（应激响应途径）、（伴侣蛋白在 ABA 信号转导中）、（编码钾通道）在枸杞中、（IAA 生物合成）在 AMF 接种的、、、、、和（多胺生物合成）在 PGPR 接种的中，14-3-3 基因（-ABA 信号通路中的基因）在 AMF 处理的中，（乙烯生物合成），在鹰嘴豆中，茉莉酸基因在鹰嘴豆中，（水杨酸调节基因），（茉莉酸标记基因）和（乙烯响应基因）在处理的中。此外，miRNA 在 MIST 中的关键作用也在 RA 处理的鹰嘴豆植物中得到了记录。
