|WIJEWARDENEA, INOSHA - Texas Tech University|
|MISHRA, NEELAM - Center For Natural Biological Resources And Community Development|
|SUNA, LI - Texas Tech University|
|SMITH, JENNIFER - Texas Tech University|
|ZHUA, XUNLU - Texas Tech University|
|SHEN, GUOXIN - Texas Tech University|
|ZHANG, HONG - Texas Tech University|
Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/6/2020
Publication Date: 4/15/2020
Citation: Wijewardenea, I., Mishra, N., Suna, L., Smith, J., Zhua, X., Payton, P.R., Shen, G., Zhang, H. 2020. Improving drought-, salinity-, and heat-tolerance in transgenic plants by co-overexpressing arabidopsis vacuolar pyrophosphatase gene AVP1 and Larrea Rubisco activase gene RCA. Plant Science. 296:110499. https://doi.org/10.1016/j.plantsci.2020.110499.
Interpretive Summary: Cotton production in the US and most parts of the world is limited by high temperature, water deficit, and often salinity. For this study, ARS scientists genetically engineered cotton plants to express genes known to be control salt tolerance and resistance to high temperature and drought stress. The result of these experiments show that plants engineered to produce increased levels of the these important genes had improved growth, total plant biomass, and seed cotton yield compared to control plants and plants that only expressed one of the genes at a time. This work shows the potential of expressing multiple genes that control multiple stress response pathways for improving cotton growth and yield.
Technical Abstract: The severity and frequency of many abiotic stresses such as drought, salinity and heat, cause substantial crop losses worldwide, which poses a serious challenge in food security. To increase crop production, new approaches are needed. Previous research has shown that overexpression of the tonoplast H+ pyrophosphatase gene AVP1 leads to improved drought and salt tolerance in transgenic plants. Other research showed that overexpression of thermotolerant ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activase gene could maintain photosynthesis at higher temperatures, which contributes to higher heat tolerance in transgenic plants. In nature, abiotic stresses rarely come alone, instead these stresses often occur in various combinations. Therefore, it is desirable to make crops more tolerant to multiple stresses, which will likely lead to higher crop yield under various stress conditions. It is shown here that co-overexpression of the Arabidopsis gene AVP1 and the Larrea Rubisco activase gene RCA significantly increases drought, salinity and heat tolerance, resulting in higher biomass and seed yield than wild-type plants. AVP1/RCA co-overexpressing plants are as more drought- and salttolerant as AVP1-overexpressing plants, and as more heat-tolerant as RCA-overexpressing plants. More importantly, they produce higher seed yields than AVP1-overexpressing, RCA-overexpressing, and wild-type plants under combined drought and heat conditions.