Overexpression of a brassinosteroid biosynthetic gene Dwarf enhances photosynthetic capacity through activation of Calvin cycle enzymes in tomato.
Overexpression of a brassinosteroid biosynthetic gene Dwarf enhances photosynthetic capacity through activation of Calvin cycle enzymes in tomato.
复制标题
油菜素类固醇生物合成基因 Dwarf 的过度表达通过激活番茄中的卡尔文循环酶来增强光合能力
DOI：
10.1186/s12870-016-0715-6
复制
发表时间：
2016-01-28
影响因子：
5.3
通讯作者：
Xia XJ
中科院分区：
文献类型：
--
作者：
Li XJ;Guo X;Zhou YH;Shi K;Zhou J;Yu JQ;Xia XJ
背景：油菜素内酯（brassinosteroids， BR）生物合成或信号传导的基因操作是提高作物产量和品质的一种很有前景的策略。然而，br促进生长与光合作用之间的关系以及br调节光合能力的确切机制尚不清楚。本研究通过过表达编码CYP85A1的BR生物合成基因Dwarf获得了转基因番茄植株，并将其光合能力与BR生物合成突变体d （im）和野生型进行了比较。结果：矮子过表达提高了净光合速率（pn），而与WT相比，d （im）中BR缺乏导致pn显著抑制。不同基因型中RuBisCO的激活状态、RuBisCO激活酶的蛋白含量和活性与内源BR水平密切相关，而RuBisCO的总含量和转录量与内源BR水平无关。而内源性BR正调控果糖-1,6-二磷酸酶的表达和活性。矮基因过表达提高了脱氢抗坏血酸还原酶和谷胱甘肽还原酶的活性，导致氧化还原状态降低，而BR缺乏则有相反的影响。此外，BR在不改变蛋白质含量的情况下诱导2-半胱氨酸过氧化物还蛋白的减少。结论：BR在光合作用中起调节作用。BR可以通过诱导氧化还原状态，维持卡尔文循环酶的激活状态来增加光合能力。
Background:Genetic manipulation of brassinosteroid (BR) biosynthesis or signaling is a promising strategy to improve crop yield and quality. However, the relationships between the BR-promoted growth and photosynthesis and the exact mechanism of BR-regulated photosynthetic capacity are not clear. Here, we generated transgenic tomato plants by overexpressing Dwarf, a BR biosynthetic gene that encodes the CYP85A1, and compared the photosynthetic capacity with the BR biosynthetic mutant d (im) and wild type.Results:Overexpression of Dwarf promoted net photosynthetic rate (P N), whereas BR deficiency in d (im) led to a significant inhibition in P N as compared with WT. The activation status of RuBisCO, and the protein content and activity of RuBisCO activase, but not the total content and transcripts of RuBisCO were closely related to the endogenous BR levels in different genotypes. However, endogenous BR positively regulated the expression and activity of fructose-1,6-bisphosphatase. Dwarf overexpression enhanced the activity of dehydroascorbate reductase and glutathione reductase, leading to a reduced redox status, whereas BR deficiency had the contrasting effects. In addition, BR induced a reduction of 2-cystein peroxiredoxin without altering the protein content.Conclusions:BR plays a role in the regulation of photosynthesis. BR can increase the photosynthetic capacity by inducing a reduced redox status that maintains the activation states of Calvin cycle enzymes.