Journal of Tea Science Research, 2024, Vol.14, No.5, 285-292 http://hortherbpublisher.com/index.php/jtsr 286 2 Genetic Basis of Stress Resistance Traits in Tea Plants Tea plants (Camellia sinensis) face multiple environmental stresses, including drought, heat, cold, and salinity, which significantly affect their growth and productivity. These stresses trigger complex molecular responses, such as alternative splicing and differential gene expression, to enhance stress adaptation. Key stress-related genes, including the bZIP, SOD, and MYB transcription factor families, play vital roles in drought, cold, and oxidative stress tolerance. Additionally, molecular signaling pathways, such as the ABA and jasmonic acid pathways, regulate stress resistance through intricate networks of transcription factors and regulatory genes. Understanding these genetic and molecular mechanisms provides valuable insights for improving tea plant resilience and developing stress-tolerant cultivars. 2.1 Effects of major environmental stresses on tea plants Ding et al. (2020) found that tea trees (Camellia sinensis) suffer from a variety of environmental stresses, including drought, high temperature, low temperature and salt stress, which significantly affect their growth and productivity. Drought and heat stresses, for instance, trigger alternative splicing in a large number of genes, enhancing the transcriptome's adaptability to these conditions. Cold stress is particularly challenging, affecting the physiological and biochemical processes in tea plants, as seen in the differential responses of cold-resistant and susceptible cultivars. Salinity stress also influences gene expression, with certain genes like the serine acetyltransferase (SAT) family playing a crucial role in enhancing salt tolerance (Ding et al., 2020). 2.2 Stress-related genes and their functions in tea plants Several gene families have been identified as key players in the stress response of tea plants. The bZIP gene family, particularly the ABF subgroup, is involved in ABA signaling and drought tolerance. The CsAFS2 gene enhances resistance to cold and insect stress by increasing protective enzyme activity and osmotic regulatory substances (Zhou et al., 2019). The superoxide dismutase (SOD) gene family is crucial for reactive oxygen species (ROS) removal, with specific genes being induced under cold and drought stress. Additionally, the MYB transcription factors are involved in jasmonic acid signal transduction, enhancing cold stress tolerance (Liu et al., 2021) (Figure 1). Figure 1 Tea tree seedling cultivation and gene expression (Adopted from Alagarsamy et al., 2018) 2.3 Molecular signaling pathways and regulatory mechanisms of stress resistance The molecular signaling pathways in tea plants involve complex networks of transcription factors and regulatory genes. The CsMYB transcription factors interact with jasmonic acid pathway components to mediate cold stress responses. The CsABF genes are part of the ABA signaling pathway, crucial for drought tolerance (Lu et al., 2021). The YUCCA gene family, involved in IAA biosynthesis, plays a role in stress resistance by regulating
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