Abscisic acid (ABA) is an important phytohormone that plays a critical role in seed development, dormancy, and stress tolerance. 9-cis-Epoxycarotenoid dioxygenase is the key enzyme controlling ABA biosynthesis and stress tolerance. In this study, we investigated the effect of ectopic expression of another ABA biosynthesis gene, ABA2 (or GLUCOSE INSENSITIVE 1 [GIN1]) encoding a short-chain dehydrogenase/reductase in Arabidopsis (Arabidopsis thaliana). We show that ABA2-overexpressing transgenic plants with elevated ABA levels exhibited seed germination delay and more tolerance to salinity than wild type when grown on agar plates and/or in soil. However, the germination delay was abolished in transgenic plants showing ABA levels over 2-fold higher than that of wild type grown on 250 mm NaCl. The data suggest that there are distinct mechanisms underlying ABA-mediated inhibition of seed germination under diverse stress. The ABA-deficient mutant aba2, with a shorter primary root, can be restored to normal root growth by exogenous application of ABA, whereas transgenic plants overexpressing ABA2 showed normal root growth. The data reflect that the basal levels of ABA are essential for maintaining normal primary root elongation. Furthermore, analysis of ABA2 promoter activity with ABA2::beta-glucuronidase transgenic plants revealed that the promoter activity was enhanced by multiple prolonged stresses, such as drought, salinity, cold, and flooding, but not by short-term stress treatments. Coincidently, prolonged drought stress treatment led to the up-regulation of ABA biosynthetic and sugar-related genes. Thus, the data support ABA2 as a late expression gene that might have a fine-tuning function in mediating ABA biosynthesis through primary metabolic changes in response to stress.
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http://dx.doi.org/10.1104/pp.106.084103 | DOI Listing |
Plant Sci
January 2025
Shanghai Agrobiological Gene Center, Shanghai, 201106 China; Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization, Ministry of Agriculture and Rural Affairs, Shanghai, 201106, China. Electronic address:
Nuclear factor Y (NF-Y) is an evolutionarily conserved heterotrimeric transcription factor in eukaryotes. In a previous study, OsNF-YB12 was confirmed to be associated with drought tolerance using the Ecotilling method. In this study, real-time quantitative RT-PCR revealed that OsNF-YB12 was induced by various abiotic stresses and phytohormones, with expression levels differing between leaves and roots.
View Article and Find Full Text PDFNat Commun
January 2025
Frontiers Science Center for Molecular Design Breeding, Beijing Key Laboratory of Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
During cold acclimation in high-latitude and high-altitude regions, japonica rice develops enhanced cold tolerance, but the underlying genetic basis remains unclear. Here, we identify CTB5, a homeodomain-leucine zipper (HD-Zip) transcription factor that confers cold tolerance at the booting stage in japonica rice. Four natural variations in the promoter and coding regions enhance cold response and transcriptional regulatory activity, enabling the favorable CTB5 allele to improve cold tolerance.
View Article and Find Full Text PDFPlanta
January 2025
School of Life Sciences and Technology, Institut Teknologi Bandung, Jl. Ganesha No. 10, Bandung, 40132, Indonesia.
The exogenous application of RNAi technology offers new promises for crops improvement. Cell-based or synthetically produced strands are economical, non-transgenic and could induce the same responses. The substantial population growth demands novel strategies to produce crops without further damaging the environment.
View Article and Find Full Text PDFViruses
December 2024
Applied Biotechnology Institute, California Polytechnic Tech Park, San Luis Obispo, CA 93407, USA.
Coronaviruses continue to disrupt health and economic productivity worldwide. Porcine epidemic diarrhea virus (PEDV) is a devastating swine disease and SARS-CoV-2 is the latest coronavirus to infect the human population. Both viruses display a similar spike protein on the surface that is a target of vaccine development.
View Article and Find Full Text PDFPlants (Basel)
January 2025
School of Architecture and Urban Planning, Anhui Jianzhu University, Hefei 230601, China.
The frequent occurrence of extreme weather conditions in the world has brought many unfavorable factors to plant growth, causing the growth and development of plants to be hindered and even leading to plant death, with abiotic stress hindering the growth and metabolism of plants due to severe uncontrollability. The WHY1 transcription factor plays a critical role in regulating gene expression in plants, influencing chlorophyll biosynthesis, plant growth, and development, as well as responses to environmental stresses. The important role of the gene in regulating plant growth and adaptation to environmental stress has become a hot research topic.
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