Plant sulphur metabolism is stimulated by photorespiration

First author: Cyril Abadie; Affiliations: Australian National University (澳大利亚国立大学): Canberra, Australia

Corresponding author: Guillaume Tcherkez

Intense efforts have been devoted to describe the biochemical pathway of plant sulphur (S) assimilation from sulphate. However, essential information on metabolic regulation of S assimilation is still lacking, such as possible interactions between S assimilation, photosynthesis and photorespiration. In particular, does S assimilation scale with photosynthesis thus ensuring sufficient S provision for amino acids synthesis? This lack of knowledge is problematic because optimization of photosynthesis is a common target of crop breeding and furthermore, photosynthesis is stimulated by the inexorable increase in atmospheric CO2. Here, we used high-resolution 33S and 13C tracing technology with NMR and LC-MS to access direct measurement of metabolic fluxes in S assimilation, when photosynthesis and photorespiration are varied via the gaseous composition of the atmosphere (CO2, O2). We show that S assimilation is stimulated by photorespiratory metabolism and therefore, large photosynthetic fluxes appear to be detrimental to plant cell sulphur nutrition.

对于植物从硫酸盐中吸收硫的生化途径已经有了很深入的研究。然而，对于硫吸收的代谢调控机制还有所欠缺，比如说硫吸收、光合作用与光呼吸之间的相互作用。尤其是，硫吸收是否会随着光合作用而增减以保证氨基酸合成的硫供应。这方面知识亟待探索，最优化光合作用是作物育种的一个普遍目标，此外，大气中二氧化碳的持续增加会不可避免地刺激植物光合作用的增强。本文中，作者利用高分辨率的硫33和碳13同位素追踪技术以及NMR和LC-MS一起来直接观测硫吸收的代谢流，其中光合作用和光呼吸变异通过调控大气中的二氧化碳和氧气比例来调整。作者的研究显示硫吸收受到光呼吸代谢的刺激，因此，大通量的光合作用似乎对植物细胞的硫营养有害。

通讯：Guillaume Tcherkez (http://biology.anu.edu.au/people/guillaume-tcherkez)

个人简介：2004年，巴黎第十一大学，博士。

研究方向：植物的同位素组成；植物碳氮代谢。

doi: https://doi.org/10.1038/s42003-019-0616-y

Journal: Communications Biology

Published date: October 16, 2019