Epi-Brassinolide Positively Affects Chlorophyll Content and Dark-Reaction Enzymes of Maize Seedlings
Epi-Brassinolide Positively Affects Chlorophyll Content and Dark-Reaction Enzymes of Maize Seedlings
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表油菜素内酯对玉米幼苗的叶绿素含量和暗反应酶有积极影响
DOI：
10.32604/phyton.2021.014811
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发表时间：
2021-11-05
影响因子：
1.7
通讯作者：
Zhang, Junjie
中科院分区：
文献类型：
--
作者：
Gao, Yuanfen;Jiang, Tinglan;Zhang, Junjie
类甾醇参与植物的许多生理过程，但其对光合暗期相关酶活性的调节作用仍不清楚。以玉米离体叶片和原生质体为材料，分别用表油菜素内酯（EBR）和油菜素唑（Brassinazole）处理，测定叶片叶绿素（a+B）和可溶性糖含量、暗反应酶活性及相关基因的表达。结果表明，0.1 μ M EBR处理48 h，叶绿素（a+B）含量增加7.4%，连续浸泡的离体叶片叶绿素（a+B）含量增加34%。此外，在细胞内，甘油三酸酯3-磷酸脱氢酶亚单位A（GAPA）、胞质FBPase（cyFBPase）、核酮糖-1，5-二磷酸羧化酶小亚基（rbcS）、磷酸烯醇丙酮酸羧化酶（PEPC）、果糖-1，6-二磷酸酶（FBPase）、Rubisco活化酶β亚基（RCA β）、核酮糖-1，5-二磷酸羧化酶大亚基（rbcL）和谷胱甘肽还原酶（GR）分别为96.8%、48.4%、79.3%、41%、85.6%、133.3%、0.1 μ M EBR组比对照组分别高68.8%和119.8%。在0.1 μ M EBR处理下，RCA、Rubisco活性和可溶性糖含量分别提高了53.4%、28.7%和35.4%。阿曲喹唑抑制这些基因的表达。然而，转录水平，蛋白质含量和一些暗反应酶的活性不能在EBR处理下同时增加。这些结果表明EBR对暗反应的影响主要在转录水平。
Brassinosteroids participate in many physiological processes in plants; however, their regulatory roles on the activities of the enzymes involved in dark phase of photosynthesis remains elusive. In this study, detached leaves and protoplasts of maize seedlings were treated with epi-brassinolide (EBR) and brassinazole followed by the determination of the contents of chlorophyll (a+b) and soluble sugars, and the activity of dark reaction enzymes and the expression of the relevant genes. The results showed that chlorophyll (a+b) content increased by 7.4% under 0.1 mu M EBR treatment for 48 h; furthermore, chlorophyll (a+b) content increased by 34% in detached leaves that were continuously soaked in brassinazole. In addition, the transcription levels of glyceraldehyde3-phosphate dehydrogenase subunit A (GAPA), cytoplasmic FBPase (cyFBPase), ribulose-1,5-bisphosphate carboxylase small subunit (rbcS), phosphoenolpyruvate carboxylase ( PEPC), fructose-1,6-bisphosphatase (FBPase), Rubisco activase beta subunit (RCA beta), ribulose-l,5-bisphosphate carboxylase large subunit (rbcL), and glutathione reductase (GR) were 96.8%, 48.4%, 79.3%, 41%, 85.6%, 133.3%, 68.8%, and 119.8% higher, respectively, in 0.1 mu M EBR than in the control group. The activity of RCA and Rubisco and soluble sugar content increased by 53.4%, 28.7%, and 35.4% under 0.1 mu M EBR. Brassinazole inhibits the expression of these genes. However, the transcription level, protein content, and activity of some dark-reaction enzymes cannot be increased at the same time under EBR treatment. These results indicate that the effect of EBR on dark-reaction is mainly in transcription level.