MsMYB206-MsMYB450-MsHY5 complex regulates alfalfa tolerance to salt stress via regulating flavonoid biosynthesis during the day and night cycles.

Flavonoids are the major secondary metabolites participating in many biological processes of plants. Although flavonoid biosynthesis has been extensively studied, its regulatory mechanisms during the day and night cycles remain poorly understood. In this study, three proteins, MsMYB206, MsMYB450, and MsHY5, were found to interact with each other, in which MsMYB206 directly transactivated two flavonoid biosynthetic genes, MsFLS and MsF3'H.

MsWRKY44 regulates Mg-K homeostasis of shoots and promotes alfalfa sensitivities to acid and Al stresses.

Mg-K homeostasis is essential for plant response to abiotic stress, but its regulation remains largely unknown. MsWRKY44 cloned from alfalfa was highly expressed in leaves and petioles. Overexpression of it inhibited alfalfa growth, and promoted leaf senescence and alfalfa sensitivities to acid and Al stresses.

PECTIN ACETYLESTERASE12 regulates shoot branching via acetic acid and auxin accumulation in alfalfa shoots.

Shoot branching is an important biological trait affecting alfalfa (Medicago sativa L.) production, but its development is complicated and the mechanism is not fully clear. In the present study, pectin acetylesterase 12 (MsPAE12) and NAM/ATAF/CUC-domain transcription factor gene (MsNAC73) were isolated from alfalfa.

The MsDHN1-MsPIP2;1-MsmMYB module orchestrates the trade-off between growth and survival of alfalfa in response to drought stress.

Dehydrins and aquaporins play crucial roles in plant growth and stress responses by acting as protector and controlling water transport across membranes, respectively. MsDHN1 (dehydrin) and MsPIP2;1 (aquaporin) were demonstrated to interact with a membrane-anchored MYB protein, MsmMYB (as mMYB) in plasma membrane under normal condition. MsDHN1, MsPIP2;1 and MsDHN1-MsPIP2;1 positively regulated alfalfa tolerance to water deficiency.

Chloroplast-targeted late embryogenesis abundant 1 increases alfalfa tolerance to drought and aluminum.

Late embryogenesis-abundant (LEA) proteins are important stress-response proteins that participate in protecting plants against abiotic stresses. Here, we investigated LEA group 3 protein MsLEA1, containing the typically disordered and α-helix structure, via overexpression and RNA interference (RNAi) approaches in alfalfa (Medicago sativa L.) under drought and aluminum (Al) stresses.

MsDjB4, a HSP40 Chaperone in Alfalfa ( L.), Improves Alfalfa Hairy Root Tolerance to Aluminum Stress.

The toxicity of aluminum (Al) in acidic soils poses a significant limitation to crop productivity. In this study, we found a notable increase in () expression in the roots of Al-tolerant alfalfa (WL-525HQ), which we named . Transient conversion assays of tobacco leaf epidermal cells showed that MsDjB4 was targeted to the membrane system including Endoplasmic Reticulum (ER), Golgi, and plasma membrane.

MsMYB741 is involved in alfalfa resistance to aluminum stress by regulating flavonoid biosynthesis.

Aluminum (Al) toxicity severely restricts plant growth in acidic soils (pH < 5.0). In this study, an R2R3-MYB transcription factor (TF) gene, MsMYB741, was cloned from alfalfa.

Dehydrin MsDHN1 improves aluminum tolerance of alfalfa (Medicago sativa L.) by affecting oxalate exudation from root tips.

A SK -type dehydrin MsDHN1 was cloned from alfalfa (Medicago sativa L.). Its function and gene regulatory pathways were studied via overexpression and suppression of MsDHN1 in alfalfa seedlings or hairy roots.

Analysis of the Function of the Alfalfa Mslea-D34 Gene in Abiotic Stress Responses and Flowering Time.

A novel late embryogenesis abundant (LEA) gene, MsLEA-D34, was cloned from alfalfa (Medicago sativa L.). Its function and gene regulatory pathways were studied via overexpression (OE) and RNA interference (RNAi) of the gene in Arabidopsis and in hairy roots of alfalfa, as well as via analyzing key genes related to MsLEA-D34 during developmental phases in alfalfa.

Interaction of zinc and IAA alleviate aluminum-induced damage on photosystems via promoting proton motive force and reducing proton gradient in alfalfa.

Background: In acidic soils, aluminum (Al) competing with Zn results in Zn deficiency in plants. Zn is essential for auxin biosynthesis. Zn-mediated alleviation of Al toxicity has been rarely studied, the mechanism of Zn alleviation on Al-induced photoinhibition in photosystems remains unclear.

Auxin Is Involved in Magnesium-Mediated Photoprotection in Photosystems of Alfalfa Seedlings Under Aluminum Stress.

The objective of this study was to investigate the effects of Mg and IAA on the photosystems of Al-stressed alfalfa ( L.). Alfalfa seedlings with or without apical buds were exposed to solutions fully mixed with 0 or 100 μM AlCl and 0 or 50 μM MgCl followed by foliar spray with water or IAA.

Characterization of cadmium-resistant rhizobacteria and their promotion effects on Brassica napus growth and cadmium uptake.

Excessive cadmium (Cd) accumulation in soil can adversely affect plants, animals, microbes, and humans; therefore, novel and uncharacterized Cd-resistant plant-growth-promoting rhizobacteria (PGPR) are required to address this issue. In the paper, 13 bacteria were screened, their partial 16S rRNA sequences determined, and the isolates, respectively, clustered into Curtobacterium (7), Chryseobacterium (4), Cupriavidus (1), and Sphingomonas (1). Evaluation of PGP traits, including indole-3-acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, siderophore secretion, and cyanhydric acid production, identified Cupriavidus necator GX_5, Sphingomonas sp.

Characterization of Dehydrin protein, CdDHN4-L and CdDHN4-S, and their differential protective roles against abiotic stress in vitro.

Background: Dehydrins play positive roles in regulating plant abiotic stress responses. The objective of this study was to characterize two dehydrin genes, CdDHN4-L and CdDHN4-S, generated by alternative splicing of CdDHN4 in bermudagrass.

Results: Overexpression of CdDHN4-L with φ-segment and CdDHN4-S lacking of φ-segment in Arabidopsis significantly increased tolerance against abiotic stresses.

Isolation and characterization of GmMYBJ3, an R2R3-MYB transcription factor that affects isoflavonoids biosynthesis in soybean.

Isoflavonoids are secondary metabolites that play a variety of roles in plant-microbe interactions and plant defenses against abiotic stresses. Here we report a new MYB transcription factor (TF) gene, GmMYBJ3, that is involved in the isoflavonoids biosynthesis. The GmMYBJ3 gene is 1,002 bp long and encodes a protein of 333 amino acids.

Gene Expression Analysis of Alfalfa Seedlings Response to Acid-Aluminum.

Acid-Aluminum (Al) is toxic to plants and greatly affects crop production worldwide. To understand the responses of plants to acid soils and Aluminum toxicity, we examined global gene expression using microarray data in alfalfa seedlings with the treatment of acid-Aluminum. 3,926 genes that were identified significantly up- or downregulated in response to Al ions with pH 4.

A novel MYB transcription factor, GmMYBJ1, from soybean confers drought and cold tolerance in Arabidopsis thaliana.

MYB transcription factors play important roles in the regulation of plant growth, developmental metabolism and stress responses. In this study, a new MYB transcription factor gene, GmMYBJ1, was isolated from soybean [Glycine max (L.)].

A R2R3-MYB transcription factor, GmMYB12B2, affects the expression levels of flavonoid biosynthesis genes encoding key enzymes in transgenic Arabidopsis plants.

Isoflavones play diverse roles in plant-microbe interactions and are potentially important for human nutrition and health. To study the regulation of isoflavonoid synthesis in soybean, the R2R3-MYB transcription factor GmMYB12B2 was isolated and characterized. Yeast expression experiments demonstrated that GmMYB12B2 showed transcriptional activity.

Isolation and molecular characterization of GmERF7, a soybean ethylene-response factor that increases salt stress tolerance in tobacco.

Ethylene-response factors (ERFs) play an important role in regulating gene expression in plant responses to biotic and abiotic stresses. In this study, a new ERF transcription factor, GmERF7, was isolated from soybean. Sequence analysis showed that GmERF7 contained an AP2/ERF domain with 58 amino acids, two putative nuclear localization signal (NLS) domains, an acidic amino acid-rich transcriptional activation domain and a conserved N-terminal motif [MCGGAI(I/L)].