Photorespiration is the major alternative electron sink under high light in alpine evergreen sclerophyllous Rhododendron species

doi:10.1016/j.plantsci.2019.110275

	Photorespiration is the major alternative electron sink under high light in alpine evergreen sclerophyllous Rhododendron species
	Huang,Wei; Yang,Ying-Jie; Wang,Ji-Hua; Hu,Hong
刊名	PLANT SCIENCE
	2019
卷号	289 页码:110275
ISSN号	0168-9452
DOI	10.1016/j.plantsci.2019.110275
英文摘要	Owing to the high leaf mass per area, alpine evergreen sclerophyllous Rhododendron have low values of mesophyll conductance (g(m)). The resulting low chloroplast CO2 concentration aggravates photorespiration, which requires a higher ATP/NADPH ratio. However, the significance of photorespiration and underlying mechanisms of energy balance in these species are little known. In this study, eight alpine evergreen sclerophyllous Rhododendron species grown in a common garden were tested for their g(m), electron flow to photorespiration, and energy balancing. Under saturating light, g(m) was the most limiting factor for net photosynthesis (A(N)) in all species, and the species differences in A(N) were primarily driven by gm rather than stomatal conductance. The total electron flow through photosystem II (ETRII) nearly equaled the electron transport required for Rubisco carboxylation and oxygenation. Furthermore, blocking electron flow to photosystem I with appropriate inhibitors showed that electron flow to plastic terminal oxidase was not observed. As a result, these studied species showed little alternative electron flow mediated by water-water cycle or plastic terminal oxidase. By comparison, the ratio of electron transport consumed by photorespiration to ETRII (J(pR)/ETRII), ranging from 43% similar to 55%, was negatively correlated to A(N) and g(m). Furthermore, the increased ATP production required by enhanced photorespiration was regulated by cyclic electron flow around photosystem I. These results indicate that photorespiration is the major electron sink for dissipation of excess excitation energy in the alpine evergreen sclerophyllous Rhododendron species. The coordination of g(m) photorespiration and cyclic electron flow is important for sustaining leaf photosynthesis.
WOS记录号	WOS:000494891900017
内容类型	期刊论文
源URL	[http://ir.kib.ac.cn/handle/151853/71048]
专题	中国科学院昆明植物研究所
推荐引用方式 GB/T 7714	Huang,Wei,Yang,Ying-Jie,Wang,Ji-Hua,et al. Photorespiration is the major alternative electron sink under high light in alpine evergreen sclerophyllous Rhododendron species[J]. PLANT SCIENCE,2019,289:110275.
APA	Huang,Wei,Yang,Ying-Jie,Wang,Ji-Hua,&Hu,Hong.(2019).Photorespiration is the major alternative electron sink under high light in alpine evergreen sclerophyllous Rhododendron species.PLANT SCIENCE,289,110275.
MLA	Huang,Wei,et al."Photorespiration is the major alternative electron sink under high light in alpine evergreen sclerophyllous Rhododendron species".PLANT SCIENCE 289(2019):110275.