Singh Shikha, Singh Anita, Srivastava Prabhat Kumar, Prasad Sheo Mohan
Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad -211002, India.
Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad -211002, India.
J Photochem Photobiol B. 2018 Jan;178:76-84. doi: 10.1016/j.jphotobiol.2017.10.025. Epub 2017 Oct 28.
The supplementation of plant hormones may enhance the tolerance capacity of plants against certain environmental stresses by increasing their physiological functioning and detoxification capacity. To answer the question that whether a phytohormone 'kinetin' (KN, 6-furfuylaminopurine), one of the artificial cytokinins could ameliorate the cadmium induced toxicity in tomato seedlings, the effect of KN was assessed in differentially cadmium (Cd: 3mgkg sand and Cd: 9mgkg sand) intoxicated tomato seedlings by estimating the changes in reactive oxygen species (ROS, viz. superoxide radical and HO generation) and probable alteration in photosystem II photochemistry, ascorbate-glutathione cycle enzymes and their metabolites. Accumulation of Cd in tomato seedlings increased the production of ROS by negatively impacting PS II photochemistry (decrease in F/F (ϕP), Ψ, ϕE and PI and increase in energy fluxes per reaction centre: ABS/RC, ET/RC, TR/RC and DI/RC) manifested by lowered fresh mass despite the accelerated activity of AsA-GSH cycle enzymes (viz. ascorbate peroxidase, APX; glutathione reductase, GR; dehydroascorbate reductase, DHAR and monodehydroascorbate reductase; MDHAR). Simultaneous application of kinetin (10μM) alleviated the negative effects on the fresh mass and lowered the ROS level by positively affecting PS II photochemistry and further rise in AsA-GSH cycle enzymes and their metabolites.
植物激素的补充可以通过增强植物的生理功能和解毒能力来提高其对某些环境胁迫的耐受能力。为了回答人工细胞分裂素之一的植物激素“激动素”（KN，6-糠氨基嘌呤）是否能改善镉对番茄幼苗的毒性这一问题，通过估计活性氧（ROS，即超氧自由基和羟基自由基的产生）的变化以及光系统II光化学、抗坏血酸-谷胱甘肽循环酶及其代谢产物可能的改变，评估了激动素在不同镉（Cd：3mg/kg沙和Cd：9mg/kg沙）中毒的番茄幼苗中的作用。镉在番茄幼苗中的积累通过对PS II光化学产生负面影响（F/F（ϕP）、Ψ、ϕE和PI降低，每个反应中心的能量通量增加：ABS/RC、ET/RC、TR/RC和DI/RC）增加了ROS的产生，尽管抗坏血酸-谷胱甘肽循环酶（即抗坏血酸过氧化物酶，APX；谷胱甘肽还原酶，GR；脱氢抗坏血酸还原酶，DHAR和单脱氢抗坏血酸还原酶；MDHAR）的活性加速，但鲜重仍降低。同时施用激动素（10μM）通过积极影响PS II光化学以及抗坏血酸-谷胱甘肽循环酶及其代谢产物的进一步增加，减轻了对鲜重的负面影响并降低了ROS水平。
