Molecular Plant Breeding 2024, Vol.15, No.6, 351-361 http://genbreedpublisher.com/index.php/mpb 354 Figure 1IbPRX17overexpression enhances salt and drought tolerance in sweet potato (Adopted from Zhang et al., 2021) Image caption: (a) Responses of IbPRX17-OE and wild-type (WT) sweet potato plants grown for 4 wk on Murashige and Skoog (MS) medium under normal conditions (normal) or subjected to 150 mM NaCl or 20% polyethylene glycol 6000 (PEG6000). (b) Responses of IbPRX17-OE and WT sweet potato plants grown hydroponically in half-strength Hoagland solution alone (normal) or with the addition of 200 mM NaCl or 20% PEG6000. Data are shown as means ± SD (n = 3). *, P < 0.05; **, P < 0.01 (significant difference from the WT at based on Student’s t-tests) (Adopted from Zhang et al., 2021) 5 Molecular Mechanisms of Stress Response 5.1 Mechanisms at the cellular and molecular levels Sweet potato, like many other plants, employs a variety of cellular and molecular mechanisms to respond to stress conditions. These mechanisms include the activation of specific genes and proteins that help the plant to cope with adverse environmental factors. For instance, the expression of certain transcription factors (TFs) such as NAC, WRKY, and MYB plays a crucial role in the plant's response to abiotic stresses like drought and salinity. These TFs regulate the expression of downstream genes involved in stress tolerance, including those that manage ion accumulation, redox reactions, and hormone signaling pathways (Meng et al., 2020; 2022; Sun et al., 2022; Zhao et al., 2022). Additionally, the plant’s response to potassium deficiency involves significant transcriptional changes. Genes related to transcriptional regulation, calcium binding, and redox signaling are differentially expressed under low potassium conditions, indicating their roles in stress adaptation (Wang et al., 2021). Moreover, miRNAs have been identified as key regulators in the salt stress response, modulating the expression of target genes involved in stress tolerance (Yang et al., 2020). 5.2 Regulatory networks involved in stress adaptation The regulatory networks that govern stress adaptation in sweet potato are complex and involve multiple layers of control, including transcriptional, post-transcriptional, and post-translational modifications. Transcription factors such as IbNAC3 and IbMYB48 have been shown to interact with other proteins and regulatory elements to modulate stress responses. For example, IbNAC3 interacts with other NAC TFs to regulate the expression of genes involved in combined salt and drought stress tolerance (Meng et al., 2022). Similarly, IbMYB48 enhances salt and drought tolerance by upregulating genes involved in ABA biosynthesis, JA signaling, and ROS scavenging (Zhao et al., 2022). Furthermore, the integration of various signaling pathways, including those mediated by plant hormones like ABA, ethylene, and jasmonic acid, plays a pivotal role in coordinating the plant’s response to stress. These hormones regulate the expression of stress-responsive genes and proteins, thereby enhancing the plant’s ability to withstand adverse conditions (Golldack et al., 2011; Haak et al., 2017; Wang et al., 2021).
RkJQdWJsaXNoZXIy MjQ4ODYzMg==