GSE196602
Constitutive expression of JASMONATE RESISTANT 1 elevates content of several jasmonates and primes Arabidopsis thaliana to better withstand drought
Purpose: In this study we investigated the role of JASMONATE RESISTANT 1 (JAR1) and JAR1 mediated JA-Ile formation in drought stress tolerance in Arabidopsis thaliana. Methods:  Global transcriptional changes in  a newly generated over-expression line (JAR1-OE; 35S::JAR1-1-YFP)),  a T-DNA insertion line in the JAR1 locus (jar1-11;SALK_034543), and wild-type Col-0 were investigated by RNA-seq analyses of rosette leaves from 32 day-old plant that were either well-watered (control) or not watered after day 18 (drought). Plants were grown on soil under long-day conditions Results: Under control conditions, using a stringent cut-off (DESeq, adjusted to FDR < 0.01 and LogFC = 1), we found only four differentially expressed genes (DEGs) between jar1-11 and Col-0,  all of them  downregulated. By contrast, we found 339 DEGs between JAR1-OE and Col-0, of which 134 were downregulated and 205 were upregulated. A comparison of the RNA-seq data from Col-0 between control and drought conditions revealed 3401 DEGs, of which 2023 were down- and 1378 upregulated. By comparison, jar1-11 plants, which were most heavily affected by drought stress, showed a much higher number (6139 in total; 2616 up- and 3523 down-regulated) of DEGs, while the more drought-tolerant JAR1-OE line displayed a lower number (2025 in total; 971 up- and 1054 down-regulated) of DEGs.  2411 DEGs were found between Col-0 and jar1-11 under drought  among which 966 genes showed a higher and 1445 genes a lower expression level in jar1-11. On the other hand, out of 998 DEGs found between Col-0 and JAR1-OE under drought, 737 genes showed a higher and 261 genes a lower expression level in JAR1-OE. Moreover, we found 391 DEGs counter-regulated between jar1-11 and JAR1-OE. Conclusion:RNA-seq analysis and additional experiments of plants under control and drought stress conditions provided insight into the molecular reprogramming caused by the alteration in JA-Ile content. Overall design: Rosette leaf samples from 32 days old wild-type (Col-0), jar1-11 and JAR1-OE plants grown under well-watered (control) and drough conditions (14 days of water withholding).