GABA does not regulate stomatal CO2 signalling in Arabidopsis
© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology.
| Veröffentlicht in: | Journal of experimental botany. - 1985. - (2024) vom: 17. Apr. |
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| Weitere Verfasser: | , , , , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article ALMTs CO2 signalling GABA MPK12 genomics stomatal movement |
| Zusammenfassung: | © The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Experimental Biology. Optimal stomatal regulation is important for plant adaptation to changing environmental conditions and for maintaining crop yield. The guard-cell signal GABA is produced from glutamate by Glutamate Decarboxylase (GAD) during a reaction that generates carbon dioxide (CO2) as a by-product. Here, we investigated a putative connection between GABA signalling and the more clearly defined CO2 signalling pathway in guard cells. The GABA-deficient mutant lines gad2-1, gad2-2 and gad1/2/4/5 were examined for stomatal sensitivity to various CO2 concentrations. Our findings show a phenotypical discrepancy between the allelic mutant lines gad2-1 and gad2-2 - a weakened CO2 response in gad2-1 (GABI_474_E05) in contrast to a wild-type response in gad2-2 (SALK_028819) and gad1/2/4/5. Through transcriptomic and genomic investigation, we traced the response of gad2-1 to a deletion of full-length Mitogen-activated protein kinase 12 (MPK12) in the GABI-KAT line, thereafter as renamed gad2-1*. Guard cell-specific complementation of MPK12 restored the gad2-1* CO2 phenotype, which confirms the proposed importance of MPK12 to CO2 sensitivity. Additionally, we found that stomatal opening under low atmospheric CO2 occurs independently of the GABA-modulated opening-channel ALMT9. Our results confirm that GABA has a role in modulating the rate of stomatal opening and closing - but not in response to CO2 per se |
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| Beschreibung: | Date Revised 17.04.2024 published: Print-Electronic Citation Status Publisher |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erae168 |