The Role of Gβ Protein in Controlling Cell Expansion via Potential Interaction with Lipid Metabolic Pathways
The Role of Gβ Protein in Controlling Cell Expansion via Potential Interaction with Lipid Metabolic Pathways
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DOI：
10.1104/pp.18.01312
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发表时间：
2019-03-01
期刊：
影响因子：
7.4
通讯作者：
Pandey, Sona
中科院分区：
文献类型：
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作者：
Choudhury, Swarup Roy;Marlin, Maria A.;Pandey, Sona
异源三聚体g蛋白影响植物生长、发育以及对生物和非生物胁迫的反应的几乎所有方面，可能是通过它们与特定效应物的相互作用。然而，这些效应物的身份及其作用机制大多是未知的。在研究不同G蛋白亚基在油籽作物Camelina （Camelina sativa）含油量调节中的作用时，我们发现了G β蛋白在控制各向异性细胞扩增中的作用。G β基因的敲低导致转基因植物在营养和生殖发育过程中纵向扩张减少，横向扩张增强，导致细胞、组织和器官形状改变。这些植物的脂肪酸和磷脂谱也发生了实质性的变化，这可能导致转基因种子的含油量增加。这种增加可能是由G β蛋白与特定的patatin样磷脂酶pPLAIII delta直接相互作用引起的。抑制G β表达的亚麻荠植物表现出更高的脂肪酶活性，并且表现出与过表达pPLAIII delta的植物相似的表型，这表明G β蛋白是pPLAIII delta的负调控因子。这些结果揭示了g蛋白介导和脂质信号/代谢途径之间的相互作用，其中特定的磷脂酶可能作为效应物控制植物的关键发育和环境反应。
Heterotrimeric G-proteins influence almost all aspects of plant growth, development, and responses to biotic and abiotic stresses in plants, likely via their interaction with specific effectors. However, the identity of such effectors and their mechanism of action are mostly unknown. While investigating the roles of different G-protein subunits in modulating the oil content in Camelina (Camelina sativa), an oil seed crop, we uncovered a role of G beta proteins in controlling anisotropic cell expansion. Knockdown of G beta genes causes reduced longitudinal and enhanced transverse expansion, resulting in altered cell, tissue, and organ shapes in transgenic plants during vegetative and reproductive development. These plants also exhibited substantial changes in their fatty acid and phospholipid profiles, which possibly leads to the increased oil content of the transgenic seeds. This increase is potentially caused by the direct interaction of G beta proteins with a specific patatin-like phospholipase, pPLAIII delta. Camelina plants with suppressed G beta expression exhibit higher lipase activity, and show phenotypes similar to plants overexpressing pPLAIII delta, suggesting that the G beta proteins are negative regulators of pPLAIII delta. These results reveal interactions between the G-protein-mediated and lipid signaling/metabolic pathways, where specific phospholipases may act as effectors that control key developmental and environmental responses of plants.