Affiliation:
1. College of Life Science, Baicheng Normal University, Baicheng 137000, China
2. State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
3. Jilin Da’an Farmland Ecosystem National Observation and Research Station, Da’an 131317, China
Abstract
Alkaline stress with high pH levels could significantly influence plant growth and survival. The enzyme 9-cis-epoxycarotenoid dioxygenase (NCED) serves as a critical bottleneck in the biosynthesis of abscisic acid (ABA), making it essential for regulating stress tolerance. Here, we show that OsNCED3-overexpressing rice lines have increased ABA content by up to 50.90% and improved transcription levels of numerous genes involved in stress responses that significantly enhance seedling survival rates. Overexpression of OsNCED3 increased the dry weight contents of the total chlorophyll, proline, soluble sugar, starch, and the activities of antioxidant enzymes of rice seedlings, while reducing the contents of O2·−, H2O2, and malondialdehyde under hydroponic alkaline stress conditions simulated by 10, 15, and 20 mmol L−1 of Na2CO3. Additionally, the OsNCED3-overexpressing rice lines exhibited a notable increase in the expression of OsNCED3; ABA response-related genes OsSalT and OsWsi18; ion homeostasis-related genes OsAKT1, OsHKT1;5, OsSOS1, and OsNHX5; and ROS scavenging-related genes OsCu/Zn-SOD, OsFe-SOD, OsPOX1, OsCATA, OsCATB, and OsAPX1 in rice seedling leaves. The results of these findings suggest that overexpression of OsNCED3 upregulates endogenous ABA levels and the expression of stress response genes, which represents an innovative molecular approach for enhancing the alkaline tolerance of rice seedlings.
Funder
Strategic Priority Research Program of the Chinese Academy of Sciences
National Key Research and Development Program of China
Science and Technology Project of the Education Department of Jilin Province
Science and Technology Development Plan Project of Baicheng city
Key Scientific and Technological Project of Jilin Province
National Natural Science Foundation of China
Technology Cooperation High-Tech Industrialization Project of Jilin Province and the Chinese Academy of Sciences
Reference87 articles.
1. Food and Agriculture Organization (2024, June 18). Management of Salt Affected Soils; Food and Agriculture Organization of the United Nations. Available online: http://www.fao.org/soils-portal/soil-management/management-of-some-problem-soils/salt-affected-soils/more-information-on-salt-affected-soils/en/.
2. Integrated proteomics and metabolomics for dissecting the mechanism of global responses to salt and alkali stress in Suaeda corniculate;Pang;Plant Soil,2016
3. Differences in growth and physiology of rice in response to different saline-alkaline stress factors;Lv;Agron. J.,2013
4. Mechanisms of plant saline-alkaline tolerance;Rao;J. Plant Physiol.,2023
5. Priming effect of abscisic acid on alkaline stress tolerance in rice (Oryza sativa L.) seedlings;Wei;Plant Physiol. Biochem.,2015