title: Heat-induced phytohormone changes are associated with disrupted early reproductive development and reduced yield in rice.
abstract: Heat stress causes morphological and physiological changes and reduces crop yield in rice (Oryza sativa). To investigate changes in phytohormones and their relationships with yield and other attributes under heat stress, four rice varieties (Nagina22, Huanghuazhan, Liangyoupeijiu, and Shanyou 63) were grown in pots and subjected to three high temperature treatments plus control in temperature-controlled greenhouses for 15 d during the early reproductive phase. Yield reductions in Nagina22, Huanghuazhan, and Liangyoupeijiu were attributed to reductions in spikelet fertility, spikelets per panicle, and grain weight. The adverse effects of high temperature were alleviated by application of exogenous 6-benzylaminopurine (6-BA) in the heat-susceptible Liangyoupeijiu. High temperature stress reduced active cytokinins, gibberellin A1(GA1), and indole-3-acetic acid (IAA), but increased abscisic acid (ABA) and bound cytokinins in young panicles. Correlation analyses and application of exogenous 6-BA revealed that high temperature-induced cytokinin changes may regulate yield components by modulating the differentiation and degradation of branches and spikelets, panicle exsertion, pollen vigor, anther dehiscence, and grain size. Heat-tolerant Shanyou 63 displayed minor changes in phytohormones, panicle formation, and grain yield under high temperature compared with those of the other three varieties. These results suggest that phytohormone changes are closely associated with yield formation, and a small reduction or stability in phytohormone content is required to avoid large yield losses under heat stress.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|Hubei Collaborative Innovation for Grain Industry, Yangtze University, Jingzhou, Hubei 434023, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|Hubei Collaborative Innovation for Grain Industry, Yangtze University, Jingzhou, Hubei 434023, China.
authors.forename: Kehui
authors.initials: K
authors.lastname: Cui
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|Hubei Collaborative Innovation for Grain Industry, Yangtze University, Jingzhou, Hubei 434023, China.
authors.forename: Wencheng
authors.initials: W
authors.lastname: Wang
authors.affiliation: MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|Hubei Collaborative Innovation for Grain Industry, Yangtze University, Jingzhou, Hubei 434023, China.
authors.forename: Shah
authors.initials: S
authors.lastname: Fahad
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|Hubei Collaborative Innovation for Grain Industry, Yangtze University, Jingzhou, Hubei 434023, China.
authors.forename: Qiuqian
authors.initials: Q
authors.lastname: Hu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|Hubei Collaborative Innovation for Grain Industry, Yangtze University, Jingzhou, Hubei 434023, China.
authors.forename: Jianliang
authors.initials: J
authors.lastname: Huang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|Hubei Collaborative Innovation for Grain Industry, Yangtze University, Jingzhou, Hubei 434023, China.
authors.forename: Lixiao
authors.initials: L
authors.lastname: Nie
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.|MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Shaobing
authors.initials: S
authors.lastname: Peng
mesh_terms: D002523:Edible Grain / Q000254:growth & development / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology; D006358:Hot Temperature; D012275:Oryza / Q000254:growth & development* / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D012098:Reproduction / Q000502:physiology
chemical_list: D010937:Plant Growth Regulators