Dataset Information

A chloroplast protein, PORC, undergoes heat-induced condensation and enhances thermotolerance in Arabidopsis

ABSTRACT: This project explores the role of chloroplast stress granules (cpSGs), specialized biomolecular condensates that form within chloroplasts under environmental stress, in enhancing plant resilience to heat. Focusing on the chlorophyll biosynthesis enzyme PROTOCHLOROPHYLLIDE OXIDOREDUCTASE C (PORC) in Arabidopsis thaliana, we demonstrate that PORC dynamically localizes to cpSGs in response to both acute (42°C) and prolonged (35°C) heat stress. Although PORC transcription remains heat-insensitive, its protein condenses into discrete puncta inside chloroplasts under elevated temperatures in a reversible and translation-dependent manner. Disruption of PORC function results in impaired thermotolerance, while overexpression enhances photosynthetic recovery, Photosystem II efficiency, and post-stress plant growth. Proteomic analyses of PORC-containing cpSGs reveal enrichment of photosynthetic proteins and stress-responsive factors, indicating that cpSGs function as protective hubs during heat stress. This study uncovers a novel mechanism of chloroplast stress adaptation and suggests that targeting cpSG dynamics and PORC activity could be a promising strategy for developing heat-resilient crops in the face of global climate challenges.

INSTRUMENT(S):

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

SUBMITTER: Peng Liu

LAB HEAD: Monika Chodasiewicz

PROVIDER: PXD065110 | Pride | 2026-05-25

REPOSITORIES: pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	17_H_S_RFP_1_Slot2-17_1_16983.d.zip	Other
	18_H_S_RFP_2_Slot2-18_1_17007.d.zip	Other
	19_H_S_RFP_3_Slot2-19_1_17032.d.zip	Other
	20_H_S_RFP_4_Slot2-20_1_17094.d.zip	Other
	PORC_Heat_S1b_Slot1-10_1_12452.d.zip	Other

Items per page:

1 - 5 of 15

Publications

Chloroplastic protein PORC undergoes heat-induced condensation and enhances thermotolerance in Arabidopsis.

Alquraish Fatema F Maruri-López Israel I Luzarowski Marcin M Hernández-Sánchez Itzell E IE Chodasiewicz Monika M

Plant physiology 20260501 1

Chloroplast stress granules (cpSGs) are emerging as dynamic suborganellar condensates that play a crucial role in mediating stress response in plants. In this study, we demonstrate that the chlorophyll biosynthesis enzyme protochlorophyllide oxidoreductase C (PORC) localizes to cpSGs in response to acute and prolonged heat stress in Arabidopsis (Arabidopsis thaliana). While PORC promoter activity was developmentally regulated and remained unresponsive to heat, PORC protein re-localized from a di ...[more]

PMID: 41992520

Similar Datasets

Project description:Aim: To identify regulatory factors that control: (1) chloroplast protein importand (2) chloroplast-to-nucleus signalling. This project is a joint proposal from the Jarvis lab which is interested in chloroplast protein import [1] and the Moller lab which is interested in plastid-to-nucleus signalling [2]. Background: The majority of chloroplast proteins are encoded in the nucleus and imported post-translationally into chloroplasts. The abundance of chloroplast proteins may therefore be regulated at multiple levels. It is well documented that the nuclear gene expression is responsive to (largely unknown) signals from the chloroplast [23] and evidence is now emerging that protein import is also a regulated process [1]. Protein import into chloroplasts is mediated by protein complexes in the outer and inner envelope membranes called Toc and Tic respectively. Biochemical studies of pea chloroplasts identified several Toc/Tic components. These proteins are mechanistic or structural components of the import apparatus. Arabidopsis homologues of the pea Toc/Tic proteins were identified by the AGI. Pea Toc34 is represented in Arabidopsis by two genes "Toc33 and Toc34" and pea Toc75 is represented by three genes. These different Tocs have different expression patterns and are proposed to have different precursor protein recognition specificities. The factors that regulate Toc expression in concert with the needs of plastids in developmentally different cells are unknown. Proposal: Two Arabidopsis mutants will be analysed. The ppi1 mutant is null for the putative precursor protein receptor Toc33 [1]and the ppi3 mutant is null for a putative component of the protein import channel Toc75-IV (on chromosome IV). ppi1 plants are yellow-green in appearance but remarkably healthy and grow only slightly more slowly than wild type. By contrast ppi3 plants are indistinguishable from wild type by eye although analysis of the mutant's chloroplast proteome is beginning to reveal some differences (K. Lilley personal communication). Gene expression changes in ppi1 are likely to be quite extensive. Retardation of chloroplast development in ppi1 will activate retrograde signalling pathways so that many nuclear photosynthetic genes are down-regulated. Changes in the expression of photosynthetic genes and of the genes responsible for mediating these responses may therefore be observed. Any regulatory and signalling genes identified will be of interest to the Moller lab. The expression of factors that regulate Toc/Tic gene expression may also be altered in ppi1. It should be possible to distinguish these factors from those involved in the general control of chloroplast gene expression by comparing the results from the two mutants. Genes affected in both mutants are more likely to be involved in regulating chloroplast import since it is unlikely that widespread changes in gene expression will be observed in ppi3. Changes in the expression of factors that regulate import post-translationallyand of the Toc/Tic genes themselves (many are on the RNA) may also be observed. References: 1. Jarvis P. et al. (1998) Science 282: 100-103. 2. Moller S.G. et al. (2001) Genes Dev. 15:90-103. 3. Jarvis P. (2001) Curr. Biol. 11: R307-R310.