Citrus plants, traditionally grown in tropical and subtropical regions, face vulnerability to cold stress, affecting yield and fruit quality. Climate change's impact on cold spells has increased the need for cold-tolerant citrus varieties. While glycine betaine (GB) has been noted for its protective role, its molecular pathways remained unclear until a recent study addressed this gap.
Published on October 23, 2024, in Horticulture Research, the study by scientists from Guangxi University of Chinese Medicine and Huazhong Agricultural University identified the PtrPAT1 gene in Poncirus trifoliata, a citrus relative known for cold resistance. The study reveals PtrPAT1's role in cold tolerance by boosting GB biosynthesis, offering a genetic tool to improve citrus cold resistance.
The research focused on PtrPAT1, part of the GRAS transcription factor family, responsive to cold stress. PtrPAT1 is localized in the nucleus and plasma membrane, activating the PtrBADH-1 gene, crucial for GB production. Genetic modification showed that overexpressing PtrPAT1 in transgenic tobacco increased GB, enhanced antioxidant enzyme activity, and improved cold tolerance. Silencing PtrPAT1 led to lower GB and increased cold sensitivity. The team identified a DNA motif, TTTCATGT, in PtrBADH-1's promoter that binds with PtrPAT1, confirming its role as a transcriptional activator.
Dr. Ji-Hong Liu highlighted, "This research marks a major breakthrough in understanding how citrus plants manage cold stress." The findings open avenues for developing cold-resistant citrus varieties. Harnessing PtrPAT1 could lead to genetically modified citrus with enhanced cold resilience, reducing crop losses. This research may inspire similar strategies in other crops, improving stress resistance in agriculture.
Source: Newswise