Abstract：
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.
摘要：
植物富A/T蛋白和锌结合蛋白(PLATZ)转录因子在植物生长过程中发挥重要作用,发育和非生物胁迫响应。然而,PLATZ如何影响植物耐旱性仍然知之甚少。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运输的基因的表达，抗氧化代谢，小肽和脱落酸（ABA）信号。在这些基因中,鉴定了PLATZ4与质膜固有蛋白2;8(PIP2;8)启动子中富含A/T的序列的直接结合。PIP2;8通过抑制气孔关闭持续降低拟南芥的耐旱性。PIP2;8位于质膜中，在非洲爪的卵母细胞中表现出水通道活性，并向上作用于PLATZ4，以调节拟南芥的干旱胁迫反应。PLATZ4通过上调ABI3(ABI3)的表达增加ABA敏感性,ABI4和ABI5。在干旱和ABA处理下，在6和3h内，植物幼苗中PLATZ4的转录本被诱导到高水平，分别。总的来说，这些发现表明，PLATZ4通过调节PIP2；8和参与ABA信号传导的基因的表达来正向影响植物的耐旱性。
