Chloroplast acetyltransferase GNAT2 acts as a redox-regulated switch for state transitions in tomato.

IF 8.1 Q1 HORTICULTURE

Molecular Horticulture Pub Date : 2025-08-06 DOI:10.1186/s43897-025-00164-0

Xiaoyun Wang, Jianghao Wu, Hongxin Li, Ying Liu, Dexian Han, Danhui Dong, Jialong Zhang, Lixin Zhang, Na Zhang, Yang-Dong Guo

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引用次数: 0

Abstract

State transition is a dynamic process to balance the amount of light energy received by photosystem I (PSI) and photosystem II (PSII) so as to maintain an optimal photosynthetic yield and to minimize photo-damage in a fluctuating light environment. Recent studies show that chloroplast acetyltransferase participates in the acetylation of photosynthetic proteins and state transitions. However, the exact molecular mechanisms are poorly understood. In this study, we characterized a chloroplast acetyltransferase in Solanum lycopersicum, SlGNAT2, and found that mutants lacking this enzyme are deficient in state transitions and retarded in growth under fluctuating light. Acetyltransferase activity assays and fluorescence measurements suggest that ⁶Lys of mature SlLhcb2 protein is a target of SlGNAT2 and might be involved in state transitions. In addition, ¹³¹Cys-related redox changes of SlGNAT2 affect its acetylation activity on SlLhcb2 and influence the assembly of the PSI-LHCI-LHCII supercomplex. Therefore, we propose that the chloroplast redox state may regulate the activity of SlGNAT2 which in turn acetylates SlLhcb2 and mediates state transitions in higher plants.

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番茄叶绿体乙酰转移酶GNAT2是氧化还原调控的状态转换开关。

状态转换是光系统I （PSI）和光系统II （PSII）在波动光环境中平衡接收光能的动态过程，以保持最佳光合产量并最大限度地减少光损伤。近年来的研究表明，叶绿体乙酰转移酶参与光合蛋白的乙酰化和状态转换。然而，确切的分子机制尚不清楚。在这项研究中，我们鉴定了茄属番茄叶绿体乙酰转移酶SlGNAT2，发现缺乏该酶的突变体在波动光下缺乏状态转换和生长迟缓。乙酰转移酶活性测定和荧光测定表明，成熟SlLhcb2蛋白的6Lys是SlGNAT2的靶标，可能参与了状态转变。此外，13cys相关的SlGNAT2氧化还原变化影响其对SlLhcb2的乙酰化活性，并影响PSI-LHCI-LHCII超配合物的组装。因此，我们认为叶绿体氧化还原状态可能调节SlGNAT2的活性，SlGNAT2反过来使SlLhcb2乙酰化并介导高等植物的状态转变。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Molecular Horticulture horticultural research-

CiteScore

8.00

自引率

0.00%

发文量

审稿时长

12 weeks

期刊介绍： Aims Molecular Horticulture aims to publish research and review articles that significantly advance our knowledge in understanding how the horticultural crops or their parts operate mechanistically. Articles should have profound impacts not only in terms of high citation number or the like, but more importantly on the direction of the horticultural research field. Scope Molecular Horticulture publishes original Research Articles, Letters, and Reviews on novel discoveries on the following, but not limited to, aspects of horticultural plants (including medicinal plants): ▪ Developmental and evolutionary biology ▪ Physiology, biochemistry and cell biology ▪ Plant-microbe and plant-environment interactions ▪ Genetics and epigenetics ▪ Molecular breeding and biotechnology ▪ Secondary metabolism and synthetic biology ▪ Multi-omics dealing with data sets of genome, transcriptome, proteome, metabolome, epigenome and/or microbiome. The journal also welcomes research articles using model plants that reveal mechanisms and/or principles readily applicable to horticultural plants, translational research articles involving application of basic knowledge (including those of model plants) to the horticultural crops, novel Methods and Resources of broad interest. In addition, the journal publishes Editorial, News and View, and Commentary and Perspective on current, significant events and topics in global horticultural fields with international interests.