A wave of specific transcript and protein accumulation accompanies pollen dehydration.

Autor:	Sze H; Department Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA., Klodová B; Institute of Experimental Botany of the Czech Academy of Sciences, 165 02 Prague 6, Czech Republic.; Department of Experimental Plant Biology, Faculty of Science, Charles University, Praha 2, 128 00, Czech Republic., Ward JM; Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN 55108, USA., Harper JF; Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA., Palanivelu R; School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA., Johnson MA; Department of Molecular, Cellular Biology, and Biochemistry, Brown University, Providence, RI 02912, USA., Honys D; Institute of Experimental Botany of the Czech Academy of Sciences, 165 02 Prague 6, Czech Republic.
Jazyk:	angličtina
Zdroj:	Plant physiology [Plant Physiol] 2024 Jun 28; Vol. 195 (3), pp. 1775-1795.
DOI:	10.1093/plphys/kiae177
Abstrakt:	In flowering plants, male gametes are immotile and carried by dry pollen grains to the female organ. Dehydrated pollen is thought to withstand abiotic stress when grains are dispersed from the anther to the pistil, after which sperm cells are delivered via pollen tube growth for fertilization and seed set. Yet, the underlying molecular changes accompanying dehydration and the impact on pollen development are poorly understood. To gain a systems perspective, we analyzed published transcriptomes and proteomes of developing Arabidopsis thaliana pollen. Waves of transcripts are evident as microspores develop to bicellular, tricellular, and mature pollen. Between the "early"- and "late"-pollen-expressed genes, an unrecognized cluster of transcripts accumulated, including those encoding late-embryogenesis abundant (LEA), desiccation-related protein, transporters, lipid-droplet associated proteins, pectin modifiers, cysteine-rich proteins, and mRNA-binding proteins. Results suggest dehydration onset initiates after bicellular pollen is formed. Proteins accumulating in mature pollen like ribosomal proteins, initiation factors, and chaperones are likely components of mRNA-protein condensates resembling "stress" granules. Our analysis has revealed many new transcripts and proteins that accompany dehydration in developing pollen. Together with published functional studies, our results point to multiple processes, including (1) protect developing pollen from hyperosmotic stress, (2) remodel the endomembrane system and walls, (3) maintain energy metabolism, (4) stabilize presynthesized mRNA and proteins in condensates of dry pollen, and (5) equip pollen for compatibility determination at the stigma and for recovery at rehydration. These findings offer novel models and molecular candidates to further determine the mechanistic basis of dehydration and desiccation tolerance in plants. Competing Interests: Conflict of interest statement. None declared. (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
Databáze:	MEDLINE
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