Ali Basharat, Gill Rafaqat A, Yang Su, Gill Muhammad B, Farooq Muhammad A, Liu Dan, Daud Muhammad K, Ali Shafaqat, Zhou Weijun
Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China.
Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China; Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat 26000, Pakistan.
PLoS One. 2015 Apr 24;10(4):e0123328. doi: 10.1371/journal.pone.0123328. eCollection 2015.
It is evident from previous reports that 5-aminolevulinic acid (ALA), like other known plant growth regulators, is effective in countering the injurious effects of heavy metal-stress in oilseed rape (Brassica napus L.). The present study was carried out to explore the capability of ALA to improve cadmium (Cd2+) tolerance in B. napus through physiological, molecular, and proteomic analytical approaches. Results showed that application of ALA helped the plants to adjust Cd2+-induced metabolic and photosynthetic fluorescence changes in the leaves of B. napus under Cd2+ stress. The data revealed that ALA treatment enhanced the gene expressions of antioxidant enzyme activities substantially and could increase the expression to a certain degree under Cd2+ stress conditions. In the present study, 34 protein spots were identified that differentially regulated due to Cd2+ and/or ALA treatments. Among them, 18 proteins were significantly regulated by ALA, including the proteins associated with stress related, carbohydrate metabolism, catalysis, dehydration of damaged protein, CO2 assimilation/photosynthesis and protein synthesis/regulation. From these 18 ALA-regulated proteins, 12 proteins were significantly down-regulated and 6 proteins were up-regulated. Interestingly, it was observed that ALA-induced the up-regulation of dihydrolipoyl dehydrogenase, light harvesting complex photo-system II subunit 6 and 30S ribosomal proteins in the presence of Cd2+ stress. In addition, it was also observed that ALA-induced the down-regulation in thioredoxin-like protein, 2, 3-bisphosphoglycerate, proteasome and thiamine thiazole synthase proteins under Cd2+ stress. Taken together, the present study sheds light on molecular mechanisms involved in ALA-induced Cd2+ tolerance in B. napus leaves and suggests a more active involvement of ALA in plant physiological processes than previously proposed.
从先前的报告中可以明显看出，5-氨基乙酰丙酸（ALA）与其他已知的植物生长调节剂一样，在对抗油菜（Brassica napus L.）中重金属胁迫的有害影响方面是有效的。本研究旨在通过生理、分子和蛋白质组学分析方法，探索ALA提高甘蓝型油菜对镉（Cd2+）耐受性的能力。结果表明，ALA的施用有助于植物在Cd2+胁迫下调节甘蓝型油菜叶片中Cd2+诱导的代谢和光合荧光变化。数据显示，ALA处理显著增强了抗氧化酶活性的基因表达，并且在Cd2+胁迫条件下可以在一定程度上增加表达。在本研究中，鉴定出34个因Cd2+和/或ALA处理而差异调节的蛋白质斑点。其中，18种蛋白质受ALA显著调节，包括与胁迫相关、碳水化合物代谢、催化、受损蛋白质脱水、CO2同化/光合作用以及蛋白质合成/调节相关的蛋白质。在这18种受ALA调节的蛋白质中，12种蛋白质显著下调，6种蛋白质上调。有趣的是，观察到在Cd2+胁迫存在的情况下，ALA诱导二氢硫辛酰胺脱氢酶、光捕获复合体光系统II亚基6和30S核糖体蛋白上调。此外，还观察到在Cd2+胁迫下，ALA诱导硫氧还蛋白样蛋白、2,3-二磷酸甘油酸、蛋白酶体和硫胺噻唑合酶蛋白下调。综上所述，本研究揭示了ALA诱导甘蓝型油菜叶片对Cd2+耐受性的分子机制，并表明ALA在植物生理过程中的参与比先前提出的更为活跃。
