Regulation of drought tolerance in Arabidopsis involves the PLATZ4‐mediated transcriptional repression of plasma membrane aquaporin PIP2;8

Abstract

SUMMARY Plant A/T‐rich protein and zinc‐binding protein (PLATZ) transcription factors play important roles in plant growth, development and abiotic stress responses. However, how PLATZ influences plant drought tolerance remains poorly understood. The present study showed that PLATZ4 increased drought tolerance in Arabidopsis thaliana by causing stomatal closure. Transcriptional profiling analysis revealed that PLATZ4 affected the expression of a set of genes involved in water and ion transport, antioxidant metabolism, small peptides and abscisic acid (ABA) signaling. Among these genes, the direct binding of PLATZ4 to the A/T‐rich sequences in the plasma membrane intrinsic protein 2;8 (PIP2;8) promoter was identified. PIP2;8 consistently reduced drought tolerance in Arabidopsis through inhibiting stomatal closure. PIP2;8 was localized in the plasma membrane, exhibited water channel activity in Xenopus laevis oocytes and acted epistatically to PLATZ4 in regulating the drought stress response in Arabidopsis. PLATZ4 increased ABA sensitivity through upregulating the expression of ABSCISIC ACID INSENSITIVE 3 (ABI3), ABI4 and ABI5. The transcripts of PLATZ4 were induced to high levels in vegetative seedlings under drought and ABA treatments within 6 and 3 h, respectively. Collectively, these findings reveal that PLATZ4 positively influences plant drought tolerance through regulating the expression of PIP2;8 and genes involved in ABA signaling.

Identification of mitogen-activated protein kinases substrates in Arabidopsis using kinase client assay

“…Among them, AT1g01550 and AT3g05090 have been suggested to be involved in plant growth by participating in auxin responses, 28 , 33 and AT3g73980, AT4g12700, AT4g30480, and AT2g16850 have been reported to be involved in abiotic stress response. 31 , 34–37 To identify the biological roles of their phosphorylation by MPKs, it is necessary to test whether the phenotypes of these knock-out mutants can be rescued by the expression of the non-phosphorylation form. In the case of unknown substrates (AT2g04235, AT2g21300, AT3g04470, AT3g19330, and AT4g18950), the biological function of them would be identified first, and then the biological function of their phosphorylation should be investigated.…”

Rice OsPLATZ3 controls ROS homeostasis by inhibiting ROS-Scavenging Activity during Tapetum Degeneration

“…The PLATZ transcription factor family plays an indispensable role in the growth and development of plants and their responses to abiotic stress. Several PLATZ family genes have been studied in Arabidopsis, maize, wheat and rice, with functions related to seed size (Wang et al, 2019; Zhou and Xue, 2019), endosperm formation (Li et al, 2017; Li et al, 2021), ROS regulation (Yamada et al, 2019), responses to high salt and drought stress (Liu et al, 2020; Liu et al, 2023), and hormone signaling pathways (Timilsina et al, 2022; Liu et al, 2023; Zhang et al, 2023). In this study, the rice OsPLATZ3 , belonging to the PLATZ gene family, is predominantly expressed in the tapetum during late anther development.…”

“…ORESARA15 ( ORE15 ) regulates the size of the root apical meristem (RAM) by balancing the actions of auxin and cytokinin signaling pathways (Timilsina et al, 2022). PLATZ4 enhances drought resistance by promoting stomatal closure and regulating genes associated with abscisic acid (ABA) signaling (Liu et al, 2023). In rice, the genes GL6 and SG6 belong to the PLATZ protein family and are involved in controlling the length and size of rice grain (Wang et al, 2019).…”

Evidence for poplar PtaPLATZ18 in the regulation of plant growth and vascular tissues development

“…AtPLATZ2 is involved in the regulation of stress tolerance as lines overexpressing AtPLATZ2 had an increased sensitivity to salt stress (Liu et al, 2020). AtPLATZ4 was found to promote drought tolerance by directly repressing Plasma membrane Intrinsic Protein 2;8 (PIP2;8) as well as by regulating genes involved in ABA signalling (Liu et al, 2023). In poplar, PtPLATZ1-4 and PtPLATZ8-9 are involved in cadmium tolerance as evidenced by heterologous expression in yeast and overexpression in poplar (Ma et al, 2023).…”

“…In addition, ORE15 was reported to be a regulator of root growth and development as it positively controls root apical meristem size in a process involving auxin and cytokinin signalling-related pathways (Timilsina et al, 2022). Transgenic Arabidopsis overexpressing AtPLATZ4 exhibited a lower fresh weight than the WT, and it was suggested that AtPLATZ4 acts as a negative regulator of growth by suppressing the expression of EXP6 and EXP16 expansin genes thereby inhibiting the expansion of the cell wall (Liu et al, 2023).…”