Ramie BnALDH genes and their potential role involved in adaptation to hydroponic culturing condition

Abstract

It is an increasing interest in developing a hydroponic culture system for ramie propagation, which provide a promising method for blocking-up the soilborne diseases. However, there is an urgent need for better understanding of ramie adaptation mechanism during hydroponic culturing under low-oxygen condition. In this study, a genome-wide study plus transcriptomic and proteomic analysis was conducted to profile the molecular responses related to ramie oxidative adaption. The results showed that aldehyde dehydrogenases (ALDHs) played important roles in molecular oxygen deficiency and anaerobic metabolism in ramie. Totally, 24 ALDH genes in ramie genome were identified and grouped into 8 superfamily. All of these 24 BnALDH genes, which are unevenly distributed on the 12 chromosomes, exhibited differential expression patterns under hydroponic and soiled culturing. The expression level of almost all the BnALDHs in leaves are lower than in the roots. The BnALDHs classified into family 2 and family 10 were up-regulated in the hydroponic cultured ramie roots. Especially, BnALDH18 belonging to family 10 showed the strongest response to low-oxygen stress. In addition, heterologous overexpression analysis of BnALDH18 in Escherichia coli showed its function for elevating tolerance to oxidative stress. The genome-wide identification and analysis of evolution and expression manner demonstrated that BnALDHs are promising and untapped genetic resources for improving oxygen deficiency tolerance of ramie under hydroponic culturing.