State Key Laboratory of Crop Biology, Shandong Engineering Research Center of Plant-Microbial Restoration for Saline-Alkali Land, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China.
Hubei Hongshan Laboratory, Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China.
Plant J. 2023 Jul;115(2):434-451. doi: 10.1111/tpj.16235. Epub 2023 Apr 19.
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.
植物 A/T 富含蛋白和锌结合蛋白（PLATZ）转录因子在植物生长、发育和非生物胁迫响应中发挥重要作用。然而，PLATZ 如何影响植物的耐旱性还知之甚少。本研究表明，PLATZ4 通过引起气孔关闭来提高拟南芥的耐旱性。转录谱分析显示，PLATZ4 影响了一组参与水和离子转运、抗氧化代谢、小肽和脱落酸（ABA）信号的基因的表达。在这些基因中，鉴定了 PLATZ4 与质膜内在蛋白 2；8（PIP2；8）启动子中富含 A/T 的序列的直接结合。PIP2；8 通过抑制气孔关闭一致降低拟南芥的耐旱性。PIP2；8 定位于质膜，在非洲爪蟾卵母细胞中表现出水通道活性，并在调节拟南芥干旱胁迫响应中与 PLATZ4 呈上位性。PLATZ4 通过上调脱落酸不敏感 3（ABI3）、ABI4 和 ABI5 的表达来提高 ABA 敏感性。在干旱和 ABA 处理下，PLATZ4 的转录本在营养期幼苗中分别在 6 和 3 小时内被诱导到高水平。总之，这些发现表明，PLATZ4 通过调节 PIP2；8 和参与 ABA 信号的基因的表达，正向影响植物的耐旱性。
