Exogenous 1',4'-trans-Diol-ABA Induces Stress Tolerance by Affecting the Level of Gene Expression in Tobacco (Nicotiana tabacum L.).

Teng Liu,Di Luo,Hong Tan,Zhe-Min Li,Cai-Xia Li,Jin-Yan Zhou,Xin-Rong Ma,Dan Shu,Juan Zhong,Jie Yang

doi:10.3390/ijms22052555

Abstract

1′,4′-trans-diol-ABA is a key precursor of the biosynthesis of abscisic acid (ABA) biosynthesis 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 differentially expressed genes (DEGs) were primarily enriched in pathways related to hormones and resistance. 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.

Highlights

Phytohormones and their analogs are widely used in the production of crops and other plants, and their exogenous application has important effects on the promotion of growth and development, improvement of stress tolerance and increase in disease resistance [1].Abscisic acid (ABA) is involved in diverse plant processes, including seed dormancy, plant growth, and fruit ripening among others [2,3]
We found that drought suppressed the growth of plants, and the leaves wilted to varying degrees
This study revealed that 10,40 -trans-diol-ABA can improve drought stress tolerance and close leaf stomata, as well as having a profound influence on the global transcription level of plant genes

Summary

Introduction

Phytohormones and their analogs are widely used in the production of crops and other plants, and their exogenous application has important effects on the promotion of growth and development, improvement of stress tolerance and increase in disease resistance [1].Abscisic acid (ABA) is involved in diverse plant processes, including seed dormancy, plant growth, and fruit ripening among others [2,3]. 10 ,40 -trans-diol-ABA was identified as an important precursor of ABA synthesis in many fungi. In Botrytis cinerea, it has been confirmed that 10 ,40 -trans-diol-ABA was the final precursor of ABA [8,9]. 10 ,40 -transdiol-ABA has not been found to be related to the known ABA biosynthetic pathway in plants, and there are only a few studies that confirmed these two compounds could be mutually transformed in different plants [13,14,15]. Since it is difficult to obtain pure 10 ,40 -trans-diol-ABA, the possible biological activity of this compound on plants remains unrevealed. In 2006, pure 10 ,40 -trans-diol-ABA was isolated from a mutant strain of B. cinerea, and its crystal structure was confirmed by X-ray diffraction analysis [17]

Methods

Results

Discussion

Conclusion