Analysis of Response of Abscisic Acid Metabolism and Signal Transduction to CO2 Enrichment in Carrots
As one of the top ten vegetables in the world,carrot has achieved annual supply due to the development of facility agriculture.Under elevated CO2 conditions,carrot yield can be enhanced while simultaneously promoting the accumulation of carotenoids.Abscisic acid(ABA)is an essential hormone controllings plants growth,development,and reaction to the environment.To investigate the molecular mechanisms of carrot ABA metabolism and signaling in response to CO2 enrichment,this study examined the physiological characteristics of ABA content and 9-cis-epoxycarotenoid dioxygenase(NCED)levels under CO2 enrichment and control conditions.Additionally,RNA-Seq was employed to analyze the expression of key genes involved in abscisic acid metabolism and signaling under CO2 enrichment conditions.The results showed that increased CO2 application inhibited ABA synthesis and reduced enzyme content.Transcriptome analysis identified 482 differentially expressed genes(DEGs),of which 16 directly responded to ABA metabolism or were related to ABA signaling,7 were related to ABA metabolism,and 9 were involved in the ABA signaling pathway.The molecular connection between CO2 sensing and ABA signaling was revealed,demonstrating that ABA not only responded strongly to changes in CO2 concentration but also participated in the signal transduction process that regulates development and growth.The results of this study provide references for further study of the mechanisms of ABA accumulation and the regulation of ABA signal transduction under CO2 enrichment.