AnDHN, a Dehydrin Protein From Ammopiptanthus nanus, Mitigates the Negative Effects of Drought Stress in Plants

Abstract

Dehydrins (DHNs) play crucial roles in a broad spectrum of abiotic stresses in model plants. However, the evolutionary role of DHNs has not been explored, and the function of DHN proteins is largely unknown in Ammopiptanthus nanus (A. nanus), an ancient and endangered legume species from the deserts of northwestern China. In this study, we isolated a drought-response gene (c195333_g1_i1) from a drought-induced RNA-seq library of A. nanus. Evolutionary bioinformatics showed that c195333_g1_i1 is an ortholog of Arabidopsis DHN, and we renamed it AnDHN. Moreover, DHN proteins may define a class of proteins that are evolutionarily conserved in all angiosperms that have experienced a contraction during the evolution of legumes. Arabidopsis plants overexpressing AnDHN exhibited morpho-physiological changes, such as an increased germination rate, higher relative water content (RWC), higher proline (PRO) content, increased peroxidase (POD) and catalase (CAT) activities, lower contents of malondialdehyde (MDA), H2O2 and O2–, and longer root length. Our results showed that the transgenic lines had improved drought resistance with deep root system architecture, excellent water retention, increased osmotic adjustment, and enhanced reactive oxygen species (ROS) scavenging. Furthermore, the transgenic lines also had enhanced salt and cold tolerance. Our findings demonstrate that AnDHN may be a good candidate gene for improving abiotic stress tolerance in crops.Key Message: Using transcriptome analysis in Ammopiptanthus nanus, we isolated a drought-responsive gene, AnDHN, that plays a key role in enhancing abiotic stress tolerance in plants, with strong functional diversification in legumes.

Seed Priming with Chitosan Improves Germination Characteristics Associated with Alterations in Antioxidant Defense and Dehydration-Responsive Pathway in White Clover under Water Stress

“…Previous study has proven that white clover seed priming with DA-6 significantly mitigated adverse effects of water stress on seed germination and seedling establishment in relation to significant accumulation of DHN and upregulation of Y2K , Y2SK , and SK2 genes encoding different types of DHNs [ 23 ]. Enhanced AnDHN or CaDHN3 expression in Arabidopsis increased seed germination and initial root length under drought stress and also promoted antioxidant capacity to alleviate drought-induced ROS accumulation in seedlings [ 52 , 53 ]. However, silencing of the CaDHN3 in pepper ( Capsicum annuum L.) plants significantly decreased drought tolerance, as demonstrated by more accumulation of ROS and MDA contents than the wild-type [ 53 ].…”

Molecular Traits for Adaptation to Drought and Salt Stress in Birch, Oak and Poplar Species

“…Thus, the up-regulation of LEA genes is a representative plant response to abiotic stress. In particular, dehydrins belonging to the LEA subfamily indirectly ensure the adaptation of model plants to adverse environmental conditions, affecting the architecture of the deep root system [41]. The interaction between the amphipathic α-helix of LEA1 and the fatty acid tails ensures the stabilization of the cell membrane [42].…”

Gene Profiling of the Ascorbate Oxidase Family Genes under Osmotic and Cold Stress Reveals the Role of AnAO5 in Cold Adaptation in Ammopiptanthus nanus

“…The original broad-leaved forest gradually turned into temperate steppe and gradually evolved into the current desert vegetation [ 7 ]. A. nanus is a rare evergreen broad-leaved shrub grown in the desert area of Central Asia, and is a relict plant in the ancient Mediterranean region [ 8 , 9 ]. A. nanus has survived the drastic climate change in Central Asia caused by the uplift of the Qinghai-Tibet Plateau.…”