Jakubowska Dagmara, Janicka Małgorzata
Department of Plant Molecular Physiology, Institute of Experimental Biology, University of Wrocław, Kanonia Street 6/8, 50-328 Wrocław, Poland.
Plant Sci. 2017 Nov;264:37-47. doi: 10.1016/j.plantsci.2017.08.007. Epub 2017 Aug 24.
The present research aim was to define the role of brassinosteroids (BRs) in plant adaptation to cadmium stress. We observed a stimulating effect of exogenous BR on the activity of two plasma membrane enzymes which play a key role in plants adaptation to cadmium stress, H-ATPase (EC 3.6.3.14) and NADPH oxidase (EC 1.6.3.1). Using anti-phosphothreonine antibody we showed that modification of PM H-ATPase activity under BR action could result from phosphorylation of the enzyme protein. Also the relative expression of genes encoding both PM H-ATPase and NADPH oxidase was affected by BR. To confirm the role of BR in the cadmium stimulating effect on activity of both studied plasma membrane enzymes, an assay in the presence of a BR biosynthesis inhibitor (propiconazole) was performed. Moreover, as a tool in our work we used commercially available plant mutants unable to BR biosynthesis or with dysfunctional BR signaling pathway, to further confirm participation of BR in plant adaptation to heavy metal stress. Presented results demonstrate some elements of the brassinosteroid-induced pathway activated under cadmium stress, wherein H-ATPase and NADPH oxidase are key factors.
本研究的目的是确定油菜素甾醇（BRs）在植物适应镉胁迫中的作用。我们观察到外源BR对两种质膜酶的活性具有刺激作用，这两种酶在植物适应镉胁迫中起关键作用，即H-ATP酶（EC 3.6.3.14）和NADPH氧化酶（EC 1.6.3.1）。使用抗磷酸苏氨酸抗体，我们表明在BR作用下质膜H-ATP酶活性的改变可能是由于该酶蛋白的磷酸化所致。此外，编码质膜H-ATP酶和NADPH氧化酶的基因的相对表达也受到BR的影响。为了证实BR在镉对两种研究的质膜酶活性的刺激作用中的作用，我们进行了在BR生物合成抑制剂（丙环唑）存在下的测定。此外，作为我们工作的工具，我们使用了无法进行BR生物合成或BR信号通路功能失调的市售植物突变体，以进一步证实BR参与植物对重金属胁迫的适应。呈现的结果证明了在镉胁迫下激活的油菜素甾醇诱导途径的一些要素，其中H-ATP酶和NADPH氧化酶是关键因素。
