RGA1 alleviates low‐light‐repressed pollen tube elongation by improving the metabolism and allocation of sugars and energy. (26th January 2023)

• Record Type: Journal Article
• Authors: Li, Hubo; Feng, Baohua; Li, Juncai; Fu, Weimeng; Wang, Wenting; Chen, Tingting; Liu, Lianmeng; Wu, Zhihai; Peng, Shaobing; Tao, Longxing; Fu, Guanfu
• Is Part Of: Plant, cell and environment. Volume 46:Number 4(2023)
• Page Start: 1363
• Page End: 1383
• Publication Date: 2023-01-26
• Subjects: energy metabolism and allocation -- low‐light stress -- rice -- sugar transport and metabolism; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.14547
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Low‐light stress compromises photosynthetic and energy efficiency and leads to spikelet sterility; however, the effect of low‐light stress on pollen tube elongation in the pistil remains poorly understood. The gene RGA1, which encodes a Gα‐subunit of the heterotrimeric G‐protein, enhanced low‐light tolerance at anthesis by preventing the cessation of pollen tube elongation in the pistil of rice plants. In this process, marked increases in the activities of acid invertase (INV), sucrose synthase (SUS) and mitochondrial respiratory electron transport chain complexes, as well as the relative expression levels of SUTs (sucrose transporter), SWEETs (sugars will eventually be exported transporters), SUSs, INVs, CINs (cell‐wall INV 1), SnRK1A (sucrose‐nonfermenting 1‐related kinase 1) and SnRK1B, were observed in OE‐1 plants. Accordingly, notable increases in contents of ATP and ATPase were presented in OE‐1 plants under low‐light conditions, while they were decreased in d1 plants. Importantly, INV and ATPase activators (sucrose and Na2 SO3, respectively) increased spikelet fertility by improving the energy status in the pistil under low‐light conditions, and the ATPase inhibitor Na2 VO4 induced spikelet sterility and decreased ATPase activity. These results suggest that RGA1 could alleviate the low‐light stress‐induced impairment of pollen tube elongation to increase spikelet fertility by promoting sucrose unloading in the pistil and improving the metabolism and allocation of energy. Summary statement: Low‐light results in spikelet sterility and threatens the security of rice production. RGA1 provides sufficient energy for pollen tube growth in the pistil of rice ( Oryza sativa ) under low‐light stress by promoting sucrose unloading as well as improving energy production, allocation and utilization