Overexpression of a Voltage-Dependent Anion-Selective Channel (VDAC) Protein-Encoding Gene, MsVDAC, from Medicago sativa Confers Cold and Drought Tolerance to Transgenic Tobacco

Abstract

Voltage-dependent anion channels (VDACs) are highly conserved proteins that are involved in the translocation of tRNA and play a key role in modulating plant senescence and multiple pathways. However, the functions of VDACs in plants are still poorly understood. Here, a novel VDAC gene was isolated and identified from alfalfa (Medicago sativa L.). MsVDAC localized to the mitochondria, and its expression was highest in alfalfa roots and was induced in response to cold, drought and salt treatment. Overexpression of MsVDAC in tobacco significantly increased MDA, GSH, soluble sugars, soluble protein and proline contents under cold and drought stress. However, the activities of SOD and POD decreased in transgenic tobacco under cold stress, while the O2- content increased. Stress-responsive genes including LTP1, ERD10B and Hxk3 were upregulated in the transgenic plants under cold and drought stress. However, GAPC, CBL1, BI-1, Cu/ZnSOD and MnSOD were upregulated only in the transgenic tobacco plants under cold stress, and GAPC, CBL1, and BI-1 were downregulated under drought stress. These results suggest that MsVDAC provides cold tolerance by regulating ROS scavenging, osmotic homeostasis and stress-responsive gene expression in plants, but the improved drought tolerance via MsVDAC may be mainly due to osmotic homeostasis and stress-responsive genes.

Overexpression of a Thioredoxin-Protein-Encoding Gene, MsTRX, from Medicago sativa Enhances Salt Tolerance to Transgenic Tobacco

“…Then, the seeds were placed evenly in Petri dishes containing moist filter paper and transferred into a growth chamber at 25 • C without light. The germinated alfalfa seeds at five days old were transplanted into plastic pots filled with vermiculite in a greenhouse and watered with 1/2 strength Hoagland nutrient solution every two days [17]. Each pot contained one seedling, and 400 pots were used.…”

TaPYL4, an ABA receptor gene of wheat, positively regulates plant drought adaptation through modulating the osmotic stress-associated processes

“…[8], ion channel and transporter [9], and antioxidant enzyme [10], etc., mainly through the abscisic acid (ABA)-dependent pathways [11].…”

“…The activation of the SnRK2 family members phosphorylates/ activates the transcription factors (TFs), membrane channels, and transcription of the stress-defensive genes essential in plant drought tolerance [9]. Therefore, further characterization on the module ABR/PP2C/SnRK2 of the ABA signaling pathway can deepen understanding the mechanisms of plant osmotic stress response underlying the ABAdependent pathways.…”

MsTHI1 overexpression improves drought tolerance in transgenic alfalfa (Medicago sativa L.)

“…A significant amount of Medicago sativa , also known as alfalfa, is grown globally as a leguminous feed crop. Alfalfa is essential for the growth of herbivorous animal husbandry and agricultural sustainability due to its high protein content and palatability and symbiotic nitrogen fixation (Yang et al, 2021 ). The alfalfa acreage has significantly risen in China since the Chinese government has started a strategy to strengthen the milk and alfalfa sectors in 2012 (Fan et al, 2018 ).…”