RESUMO
The Arabidopsis histone deacetylase 6 (HDA6) mutant exhibits increased tolerance to drought stress by negatively regulating the expression of ALDH2B7 and PDC1. Therefore, it was logical to determine if transgenic Arabidopsis plants expressing PDC1 or ALDH2B7 using a suitable promoter would also exhibit tolerance to drought stress. An analysis of published microarray data indicated the up-regulation of the TSPO gene, which encodes an outer membrane tryptophan-rich sensory protein (TSPO), by drought stress. RT-qPCR, as well as GUS analysis of the promoter, confirmed the up-regulation of TSPO by drought stress in Arabidopsis roots and shoots. Thus, the TSPO promoter was used to drive drought-responsive expression of ALDH2B7 and PDC1. RT-qPCR analysis confirmed that the expression of PDC1 and ALDH2B7 was up-regulated, relative to WT plants, by drought stress in homozygous pTSPO-PDC1 and pTSPO-ALDH2B7 plant lines. pTSPO-ALDH2B7 and pTSPO-PDC1 transgenic lines showed prolonged survival under drought stress. Microarray analyses revealed transcriptomic changes related to metabolism in pTSPO-PDC1 plants, indicating that selective regulation of metabolism may occur; resulting in the acquisition of drought stress tolerance. These results confirmed that TSPO promoter can be used to elevate the expression of acetic acid biosynthesis pathway genes; ensuring prolonged survival under drought stress in Arabidopsis.
Assuntos
Ácido Acético/metabolismo , Aldeído Desidrogenase/genética , Arabidopsis/genética , Proteínas de Drosophila/genética , Proteínas de Membrana/genética , Piruvato Descarboxilase/genética , Estresse Fisiológico , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Secas , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Regiões Promotoras Genéticas , Regulação para CimaRESUMO
This corrects the article DOI: 10.1038/nplants.2017.97.
RESUMO
Water deficit caused by global climate changes seriously endangers the survival of organisms and crop productivity, and increases environmental deterioration1,2. Plants' resistance to drought involves global reprogramming of transcription, cellular metabolism, hormone signalling and chromatin modification3-8. However, how these regulatory responses are coordinated via the various pathways, and the underlying mechanisms, are largely unknown. Herein, we report an essential drought-responsive network in which plants trigger a dynamic metabolic flux conversion from glycolysis into acetate synthesis to stimulate the jasmonate (JA) signalling pathway to confer drought tolerance. In Arabidopsis, the ON/OFF switching of this whole network is directly dependent on histone deacetylase HDA6. In addition, exogenous acetic acid promotes de novo JA synthesis and enrichment of histone H4 acetylation, which influences the priming of the JA signalling pathway for plant drought tolerance. This novel acetate function is evolutionarily conserved as a survival strategy against environmental changes in plants. Furthermore, the external application of acetic acid successfully enhanced the drought tolerance in Arabidopsis, rapeseed, maize, rice and wheat plants. Our findings highlight a radically new survival strategy that exploits an epigenetic switch of metabolic flux conversion and hormone signalling by which plants adapt to drought.
