Comparative genomic analysis of the aldehyde dehydrogenase gene superfamily in Arabidopsis thaliana – searching for the functional key to hypoxia tolerance

Abstract

Flooding entails different stressful conditions leading to low oxygen availability for respiration and as a result plants experience hypoxia. Stress imposed by hypoxia affects cellular metabolism, including the formation of toxic metabolites that dramatically reduce crop productivity. Aldehyde dehydrogenases (ALDHs) are a group of enzymes participating in various aspects of plant growth, development and stress responses. Although we have knowledge concerning the multiple functionalities of ALDHs in tolerance to various stresses, the engagement of ALDH in plant metabolism adjustment to hypoxia is poorly recognized. Therefore, we explored the ALDH gene superfamily in the model plant Arabidopsis thaliana. Genome-wide analyses revealed that 16 AtALDH genes are organized into ten families and distributed irregularly across Arabidopsis 5 chromosomes. According to evolutionary relationship studies from different plant species, the ALDH gene superfamily is highly conserved. AtALDH2 and ALDH3 are the most numerous families in plants, while ALDH18 was found to be the most distantly related. The analysis of cis-acting elements in promoters of AtALDHs indicated that AtALDHs participate in responses to light, phytohormones and abiotic stresses. Expression profile analysis derived from qRT-PCR showed the AtALDH2B7, AtALDH3H1 and AtALDH5F1 genes as the most responsive to hypoxia stress. In addition, the expression of AtALDH18B1, AtALDH18B2, AtALDH2B4, and AtALDH10A8 was highly altered during the post-hypoxia-reoxygenation phase. Taken together, we provide comprehensive functional information on the ALDH gene superfamily in Arabidopsis during hypoxia stress and highlight ALDHs as a functional element of hypoxic systemic responses. These findings might help develop a framework for application in the genetic improvement of crop plants.

Functional Characterization of Aldehyde Dehydrogenase in Fusarium graminearum

“…Through oxidation and dehydrogenation, ALDH can convert aldehydes into nontoxic carboxylic acids, which provide protection and detoxification to living organisms but are also associated with stress. ALDHs are upregulated in response to various forms of stress in organisms, including bacteria (due to environmental and chemical stress) [32,37], plants (such as dehydration, salinity, and oxidative stress) [15,38,39], yeast (ethanol exposure and oxidative stress) [18,40], mammals (from oxidative stress and lipid peroxidation) [41], and M. oryzae (which promotes oxidative and reductive stress tolerance) [21]. In this study, we examined the responses of seven ALDH-deficient mutants to different stressors.…”

“…Grape ALDH genes are essential for grape development, and some have been observed to be reactive to salt stress or drought [6]. Comparative genomic analyses of the ALDH gene superfamily in Arabidopsis thaliana have demonstrated that ALDH is a critical factor in hypoxia tolerance [15]. The role of ALDH in both human and yeast cells has also been extensively studied, as ALDH removes detrimental aldehydes.…”

Study on molecular mechanism of volatiles variation during Bupleurum scorzonerifolium root development based on metabolome and transcriptome analysis

“…In total, 24 ALDH families (ALDH1-24) were reported. Among them, ALDH2 and ALDH3 families are the most abundant in plants, with the former oxidizing mainly short-chain fatty aldehydes and the latter preferentially oxidizing medium-to long-chain fatty aldehydes (Stiti et al, 2021;Guan et al, 2022). Of the three genes encoding ALDH, BsALDH1 and BsALDH2 were classified as ALDH3, and BsALDH3 was classified as ALDH2, which contributed to the conversion of short or medium-chain fatty aldehydes to the corresponding fatty acids.…”