AUTHOR=Sun Yibo , Liu Linghao , Sun Shaokun , Han Wangzhen , Irfan Muhammad , Zhang Xiaojia , Zhang Li , Chen Lijing 

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

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.788938

DOI=10.3389/fpls.2021.788938

ISSN=1664-462X

ABSTRACT=<p>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 <italic>Ammopiptanthus nanus</italic> (<italic>A. nanus</italic>), an ancient and endangered legume species from the deserts of northwestern China. In this study, we isolated a drought-response gene (<italic>c195333_g1_i1</italic>) from a drought-induced RNA-seq library of <italic>A. nanus</italic>. Evolutionary bioinformatics showed that c195333_g1_i1 is an ortholog of <italic>Arabidopsis</italic> 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 <italic>AnDHN</italic> 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), H<sub>2</sub>O<sub>2</sub> and O<sub>2</sub><sup>–</sup>, 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 <italic>AnDHN</italic> may be a good candidate gene for improving abiotic stress tolerance in crops.</p><p><bold>Key Message:</bold> Using transcriptome analysis in <italic>Ammopiptanthus nanus</italic>, we isolated a drought-responsive gene, <italic>AnDHN</italic>, that plays a key role in enhancing abiotic stress tolerance in plants, with strong functional diversification in legumes.</p>