Sub-high Temperature and High Light Intensity Induced Irreversible Inhibition on Photosynthesis System of Tomato Plant (Solanum lycopersicum L.).

Tao Lu,Mingfang Qi,Zhaojuan Meng,Guoxian Zhang,Zhouping Sun,Yufeng Liu,Tianlai Li

doi:10.3389/fpls.2017.00365

Abstract

High temperature and high light intensity is a common environment posing a great risk to organisms. This study aimed to elucidate the effects of sub-high temperature and high light intensity stress (HH, 35°C, 1000 μmol⋅m-2⋅s-1) and recovery on the photosynthetic mechanism, photoinhibiton of photosystem II (PSII) and photosystem I (PSI), and reactive oxygen (ROS) metabolism of tomato seedlings. The results showed that with prolonged stress time, net photosynthetic rate (Pn), Rubisco activity, maximal photochemistry efficiency (Fv/Fm), efficient quantum yield and electron transport of PSII [Y(II) and ETR(II)] and PSI [Y(I) and ETR(I)] decreased significantly whereas yield of non-regulated and regulated energy dissipation of PSII [Y(NO) and Y(NPQ)] increased sharply. The donor side limitation of PSI [Y(ND)] increased but the acceptor side limitation of PSI [Y(NA)] decreased. Content of malondialdehyde (MDA) and hydrogen peroxide (H2O2) were increased while activity of superoxide dismutase (SOD) and peroxidase (POD) were significantly inhibited compared with control. HH exposure affected photosynthetic carbon assimilation, multiple sites in PSII and PSI, ROS accumulation and elimination of Solanum lycopersicum L.

Highlights

“Liaoyuanduoli” is an infinite-growth-typed tomato plant containing lots of properties including high quality and diseases resistance, high and stable yield, low temperature and low light tolerance, extensive adaptability and so on
It is necessary to find out the mechanisms underlying the inhibition of Photosystem I (PSI) and Photosystem II (PSII) involved in sub-high temperature and high light intensity
The excited energy is transmitted to PSII and PSI reaction centers where charge separation happens and photosynthetic electron transportation is initiated by singlet excited state of chlorophyll

Summary

Introduction

“Liaoyuanduoli” is an infinite-growth-typed tomato plant containing lots of properties including high quality and diseases resistance, high and stable yield, low temperature and low light tolerance, extensive adaptability and so on It is suitable for cultivation in both open field and protected field and it has a large area of cultivation in north China. Activity of Rubisco, photochemical activity of PSII and PSI, generation and removal of ROS, the expressions of related genes were analyzed with tomato seedlings under sub-high temperature and high light intensity at 35◦C and 1000 μmolm−2s−1 (HH). Their recovery at 25◦C and 500 μmolm−2s−1 was determined. The results provide insights into the relationship among CO2 assimilation, photosynthetic electron transport, photoinhibition, and ROS metabolism of tomato leaves under HH stress

Objectives

Methods

Findings

Discussion

Conclusion