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ARTICLE

Photoprotective Effects of D1 Protein Turnover and the Lutein Cycle on Three Ephemeral Plants under Heat Stress

by Minmin Xiao¹, Moxiang Cheng¹, Shuangquan Xie¹, Xiushuang Wang¹, Xingming Hao², Li Zhuang^1,*

1 College of Life Sciences, Shihezi University, Shihezi, 832003, China
2 State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China

* Corresponding Author: Li Zhuang. Email:

(This article belongs to the Special Issue: Plant–Environment Interactions)

Phyton-International Journal of Experimental Botany 2023, 92(6), 1841-1857. https://doi.org/10.32604/phyton.2023.027369

Received 28 October 2022; Accepted 09 January 2023; Issue published 11 April 2023

Abstract

To clarify the characteristics of photoinhibition and the primary defense mechanisms of ephemeral plant leaves against photodestruction under high temperature stress, inhibitors and the technology to determine chlorophyll fluorescence were used to explore the protective effects of D1 protein turnover and the lutein cycle in the high temperature stress of the leaves of three ephemeral plants. The results showed that the maximum light conversion efficiency (Fv/Fm) of the ephemeral plant leaves decreased, and the initial fluorescence (Fo) increased under 35°C ± 1°C heat stress for 1–4 h or on sunny days in the summer. Both Fv/Fm and Fo could be recovered after 8 h of darkness or afternoon weakening of the external temperature. Streptomycin sulfate (SM) or dithiothreitol (DTT) accelerated the decrease of Fv/Fm and the photochemical quenching coefficient (qP) in the leaves of three ephemeral plants at high temperature, and the decrease was greater in the SM than in the DTT treatment. When the high temperature stress was prolonged, the Y(II) values of light energy distribution parameters of PSII decreased, and the Y(NPQ) and Y(NO) values increased gradually in all the treatment groups of the three ephemeral plants. The results showed that the leaves of the three ephemeral plants had their own highly advanced mechanisms to protect against photodamage, which inhibited the turnover of D1 protein and xanthophyll cycle. This can damage the PSII reaction center in the leaves of the three ephemeral plants under high temperature. The protective effect of D1 protein turnover on heat stress in Erodium oxyrrhynchum and Senecio subdentatus was greater than that of the lutein cycle, while the protective effect of lutein cycle was greater than that of D1 protein turnover in Heliotropium acutiflorum subjected to heat damage.

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Keywords

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