SiASR4, the Target Gene of SiARDP from Setaria italica, Improves Abiotic Stress Adaption in Plants

Abstract

Drought and other types of abiotic stresses negatively affect plant growth and crop yields. The abscisic acid-, stress-, and ripening-induced (ASR) proteins play important roles in the protection of plants against abiotic stress. However, the regulatory pathway of the gene encoding this protein remains to be elucidated. In this study, the foxtail millet (Setaria italica) ASR gene, SiASR4, was cloned and characterized. SiASR4 localized to the cell nucleus, cytoplasm and cytomembrane, and the protein contained 102 amino acids, including an ABA/WDS (abscisic acid/water-deficit stress) domain, with a molecular mass of 11.5 kDa. The abundance of SiASR4 transcripts increased after treatment with ABA, NaCl, and PEG in foxtail millet seedlings. It has been reported that the S. italica ABA-responsive DRE-binding protein (SiARDP) binds to a DNA sequence with a CCGAC core and that there are five dehydration-responsive element (DRE) motifs within the SiASR4 promoter. Our analyses demonstrated that the SiARDP protein could bind to the SiASR4 promoter in vitro and in vivo. The expression of SiASR4 increased in SiARDP-overexpressing plants. SiASR4-transgenic Arabidopsis and SiASR4-overexpressing foxtail millet exhibited enhanced tolerance to drought and salt stress. Furthermore, the transcription of stress-responsive and reactive oxygen species (ROS) scavenger-associated genes was activated in SiASR4 transgenic plants. Together, these findings show that SiASR4 functions in the adaption to drought and salt stress and is regulated by SiARDP via an ABA-dependent pathway.

Genome-wide characterization of the abscisic acid-, stress- and ripening-induced (ASR) gene family in wheat (Triticum aestivum L.)

“…Overexpression of OsASR5, SiASR1 and wheat ASR1 enhanced osmotic stress and drought tolerance in transgenic plants [16,21,34]. SiASR4 and HvASR5-overexpressing transgenic plants exhibited enhanced tolerance to drought and salt stress [33,94]. Various binding sites of TFs involved in various stresses regulation, like drought, salt, heat and cold, were found in the promoter regions of TaASR genes.…”

“…The 33 TaASR proteins could be clustered into six groups with uneven numbers of family members, 10 in group I (TaASR1D-3A2) representing the largest group of ASRs, 3 in group II (TaASR4D-4A) and III (TaASR5A-5D), 5 in group IV (TaASR6D-7D2) and V (TaASR8B-9D), and 7 in group VI (TaASR10A1-10A6), respectively. To further compare the evolutionary relationships of ASR proteins, a phylogenetic tree was constructed using the protein sequences of ASR genes from wheat (33), Brachypodium distachyon (6), common bean (2), foxtail millet (6), maize (10), rice (6), sorghum (7) and soybean (3) ( Fig. 1, Additional file 1: Table S1).…”

“…The transgenic rice with overexpression of OsASR1 and transgenic maize with overexpression of ZmASR1 increased their cold tolerance [36,43]. Transgenic Arabidopsis plants with overexpression of ipomoea pes-caprae IpASR and oxtail millet SiASR4 both enhanced the tolerance to salt stress [33,44].…”

“…Increasing evidences showed that ASR proteins play important roles in plant growth and fruit ripening [1,[25][26][27], as well as in regulation of floral development and flowering time [15,28,29]. The ASR proteins have been well documented for their responses to multiple abiotic stresses, including drought, salt, heat, cold, and exposure to cadmium (Cd) and aluminum (Al) [9,24,[30][31][32][33][34][35][36][37][38].…”

“…Phylogenetic analysis of ASR proteins among wheat(33), maize(10), sorghum (7), rice (6), foxtail millet (6), Brachypodium distachyon(6), soybean (3) and common bean(2) …”