Brassinosteroids promote starch synthesis and the implication in low-light stress tolerance in Solanum lycopersicum
Brassinosteroids promote starch synthesis and the implication in low-light stress tolerance in Solanum lycopersicum
复制标题
油菜素类固醇促进淀粉合成及其对番茄耐弱光胁迫的影响
DOI：
10.1016/j.envexpbot.2022.104990
复制
发表时间：
2022-07-14
影响因子：
5.7
通讯作者：
Xia, Xiaojian
中科院分区：
文献类型：
--
作者：
Liu, Yue;Qi, Zhenyu;Xia, Xiaojian
淀粉作为植物体内碳水化合物的储存形式，在光合作用关闭时可降解为可溶性糖，以满足新陈代谢的需要。然而，淀粉合成在温室作物长期弱光胁迫中的作用尚不清楚。在这项研究中，我们发现油菜素内酯（BRs）合成基因DWARF（DWF）的过度表达增加了番茄叶片中淀粉和可溶性糖的积累，而BRs缺陷突变体dwf则表现出相反的变化。编码淀粉合成酶如颗粒结合淀粉合酶（GBSS）和ADP-葡萄糖焦磷酸化酶（AGPase）的基因表达通过DWF的过表达而显着增强，但在dwf突变体中降低。 GBSS 和 AGPase 的酶活性受 BR 以类似的方式调节。外源24-表油菜素内酯（EBR）还可以增加淀粉合成并促进植物生长。此外，增加 BR 合成或外源 EBR 可以延缓衰老并增强植物在长时间弱光胁迫下的表现。我们的结果表明，BRs 诱导的弱光胁迫与淀粉合成密切相关。该研究加深了我们对BR在碳水化合物代谢中的作用的理解，并暗示了BR在应对全球气候变化背景下的弱光胁迫中的应用。
Starch, as the stored form of carbohydrates in plants, can be degraded into soluble sugars to meet the needs of metabolism when photosynthesis is closed. However, the role of starch synthesis in response to prolonged low light stress in greenhouse crops is unclear. In this study, we found that overexpression of brassinosteroids (BRs) synthesis gene DWARF (DWF) increased accumulation of starch and soluble sugars in tomato leaves, whereas BRs deficient mutant dwf exhibited the opposite changes. The expressions of genes encoding the starch synthesis enzymes such as granule bound starch synthase (GBSS) and ADP-glucose pyrophosphorylase (AGPase) were significantly enhanced by overexpression of DWF, but decreased in dwf mutant. The enzyme activities of GBSS and AGPase were regulated by BRs in a similar way. Exogenous 24-epibrassinolide (EBR) also increased starch synthesis and promoted plant growth. Furthermore, increasing BRs synthesis or exogenous EBR delayed senes-cence and enhanced plant performance under prolonged low light stress. Our results demonstrated that BRs-induced low light stress was closely associated with starch synthesis. The study deepened our understanding on the roles of BR in carbohydrate metabolism, and implicated the application of BRs in coping with the low light stress in a context of global climate changes.