Acid invertase confers heat tolerance in rice plants by maintaining energy homoeostasis of spikelets. (17th February 2020)

• Record Type: Journal Article
• Authors: Jiang, Ning; Yu, Pinghui; Fu, Weimeng; Li, Guangyan; Feng, Baohua; Chen, Tingting; Li, Hubo; Tao, Longxing; Fu, Guanfu
• Is Part Of: Plant, cell and environment. Volume 43:Number 5(2020)
• Page Start: 1273
• Page End: 1287
• Publication Date: 2020-02-17
• Subjects: acid invertase -- energy homeostasis -- heat stress -- rice -- spikelet fertility; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.13733
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Heat stress impairs both pollen germination and pollen tube elongation, resulting in pollination failure caused by energy imbalance. Invertase plays a critical role in the maintenance of energy homoeostasis; however, few studies investigated this during heat stress. Two rice cultivars with different heat tolerance, namely, TLY83 (heat tolerant) and LLY722 (heat susceptible), were subjected to heat stress. At anthesis, heat stress significantly decreased spikelet fertility, accompanied by notable reductions in pollen germination on stigma and pollen tube elongation in ovule, especially in LLY722. Acid invertase (INV), rather than sucrose synthase, contributed to sucrose metabolism, which explains the different tolerances of both cultivars. Under heat stress, larger enhancements in NAD(H), ATP, and antioxidant capacity were found in TLY83 compared with LLY722, whereas a sharp reduction in poly(ADP‐ribose) polymerase (PARP) activity was found in the former compared with the latter. Importantly, exogenous INV, 3‐aminobenzamide (a PARP inhibitor), sucrose, glucose, and fructose significantly increased spikelet fertility under heat stress, where INV activity was enhanced and PARP activity was inhibited. Therefore, INV can balance the energy production and consumption to provide sufficient energy for pollen germination and pollen tube growth under heat stress. Abstract : Invertase can reduce spikelet sterility caused by heat stress. Invertase enhances ATP and NAD(H) production and inhibits PARP activity to maintain energy homoeostasis under heat stress. This function of invertase provides sufficient energy for pollen germination on stigma and pollen tube growth in pistil and thus heat tolerance.