Interplay between ABA and GA Modulates the Timing of Asymmetric Cell Divisions in the Arabidopsis Root Ground Tissue

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• 作者：Shin Ae Lee¹ ; Sejeong Jang¹ ; ⁵ ; Eun Kyung Yoon¹ ; ⁵ ; Jung-Ok Heo¹ ; ⁶ ; Kwang Suk Chang¹ ; ⁷ ; Ji Won Choi¹ ; Souvik Dhar¹ ; Gyuree Kim¹ ; Jeong-Eun Choe¹ ; Jae Bok Heo² ; Chian Kwon³ ; Jae-Heung Ko⁴ ; Yong-Sic Hwang¹ ; Jun Lim¹ ; ^{jlim@konkuk.ac.kr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：ABA ; GA ; GRAS ; ground tissue ; root development ; transcription factor
• 刊名：Molecular Plant
• 出版年：2016
• 出版时间：6 June 2016
• 年：2016
• 卷：9
• 期：6
• 页码：870-884
• 全文大小：2501 K

文摘

In multicellular organisms, controlling the timing and extent of asymmetric cell divisions (ACDs) is crucial for correct patterning. During post-embryonic root development in Arabidopsis thaliana, ground tissue (GT) maturation involves an additional ACD of the endodermis, which generates two different tissues: the endodermis (inner) and the middle cortex (outer). It has been reported that the abscisic acid (ABA) and gibberellin (GA) pathways are involved in middle cortex (MC) formation. However, the molecular mechanisms underlying the interaction between ABA and GA during GT maturation remain largely unknown. Through transcriptome analyses, we identified a previously uncharacterized C₂H₂-type zinc finger gene, whose expression is regulated by GA and ABA, thus named GAZ (GA- AND ABA-RESPONSIVE ZINC FINGER). Seedlings ectopically overexpressing GAZ (GAZ-OX) were sensitive to ABA and GA during MC formation, whereas GAZ-SRDX and RNAi seedlings displayed opposite phenotypes. In addition, our results indicated that GAZ was involved in the transcriptional regulation of ABA and GA homeostasis. In agreement with previous studies that ABA and GA coordinate to control the timing of MC formation, we also confirmed the unique interplay between ABA and GA and identified factors and regulatory networks bridging the two hormone pathways during GT maturation of the Arabidopsis root.