Article exogenous 1′,4′-trans-diol-aba induces stress tolerance by affecting the level of gene expression in tobacco (Nicotiana tabacum l.)

Abstract

1′,4′-trans-diol-ABA is a key precursor of the biosynthesis of abscisic acid (ABA) biosyn-thesis in fungi. We successfully obtained the pure compound from a mutant of Botrytis cinerea and explored its function and possible mechanism on plants by spraying 2 mg/L 1′,4′-trans-diol-ABA on tobacco leaves. Our results showed that this compound enhanced the drought tolerance of tobacco seedlings. A comparative transcriptome analysis showed that a large number of genes responded to the compound, exhibiting 1523 genes that were differentially expressed at 12 h, which increased to 1993 at 24 h and 3074 at 48 h, respectively. The enrichment analysis demonstrated that the differ-entially expressed genes (DEGs) were primarily enriched in pathways related to hormones and re-sistance. The DEGs of transcription factors were generally up-regulated and included the bHLH, bZIP, ERF, MYB, NAC, WRKY and HSF families. Moreover, the levels of expression of PYL/PYR, PP2C, SnRK2, and ABF at the ABA signaling pathway responded positively to exogenous 1′,4′-trans-diol-ABA. Among them, seven ABF transcripts that were detected were significantly up-regulated. In addition, the genes involved in salicylic acid, ethylene and jasmonic acid pathways, reactive oxygen species scavenging system, and other resistance related genes were primarily induced by 1′,4′-trans-diol-ABA. These findings indicated that treatment with 1′,4′-trans-diol-ABA could improve tolerance to plant abiotic stress and potential biotic resistance by regulating gene expression, similar to the effects of exogenous ABA.