Transcriptome and functional analyses reveal ERF053 from Medicago falcata as key regulator in drought resistances

Abstract

Medicago falcata L. is an important legume forage grass with strong drought resistant, which could be utilized as an important gene pool in molecular breed of forage grass. In this study, M. falcata seedlings were treated with 400 mM mannitol to simulate drought stress, and the morphological and physiological changes were investigated, as well as the transcriptome changes of M. falcata seedlings at different treatment time points (0 h, 2 h, 6 h, 12 h, 24 h, 36 h and 48 h). Transcriptome analyses revealed four modules were closely related with drought response in M. falcata by WGCNA analysis, and four ERF transcription factor genes related with drought stress were identified (MfERF053, MfERF9, MfERF034 and MfRAP2.1). Among them, MfERF053 was highly expressed in roots, and MfERF053 protein showed transcriptional activation activity by transient expression in tobacco leaves. Overexpression of MfERF053 in Arabidopsis improved root growth, number of lateral roots and fresh weight under drought, salt stress and exogenous ABA treatments. Transgenic Arabidopsis over-expressing MfERF053 gene grew significantly better than the wild type under both drought stress and salt stress when grown in soil. Taken together, our strategy with transcriptome combined WGCNA analyses identified key transcription factor genes from M. falcata, and the selected MfERF053 gene was verified to be able to enhance drought and salt resistance when over-expressed in Arabidopsis.

Molecular Mechanisms of Alfalfa (Medicago sativa L.) in Response to Combined Drought and Cold Stresses

“…Plants activate various mechanisms to cope with adversities such as drought and cold, minimizing the resulting damage [2]. Alfalfa research has transitioned from phenotypic, agronomic traits, and physiological characteristics to deeper molecular-level methodologies such as transcriptomics, metabolomics, proteomics, genomics, and genome-wide association analysis (GWAS) to identify stress-related genes [3,4]. In recent years, scholars worldwide have conducted a series of stress-resistance studies on cold and drought and achieved significant results.…”

“…As the duration of drought stress increased, MDA and Pro contents increased, and antioxidative enzyme activities such as SOD, POD, and CAT also increased. Through transcriptome sequencing, drought stress-related ERF transcription factor genes such as MfERF053, MfER9, MfER034, and MfRAP2.1 were successfully identified [15]. According to the complete alfalfa genome, the alfalfa-specific gene MsASG166 plays a positive regulatory role in the response to drought stress [16].…”