YUCCA4 overexpression modulates auxin biosynthesis and transport and influences plant growth and development via crosstalk with abscisic acid in Arabidopsis thaliana

• Autor(a) principal: Munguía-Rodríguez,Aarón Giovanni
• Data de Publicação: 2020
• Outros Autores: López-Bucio,Jesús Salvador, Ruiz-Herrera,León Francisco, Ortiz-Castro,Randy, Guevara-García,Ángel Arturo, Marsch-Martínez,Nayelli, Carreón-Abud,Yazmín, López-Bucio,José, Martínez-Trujillo,Miguel
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Genetics and Molecular Biology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000100302
• topic: Arabidopsis; auxin; abscisic acid; YUCCA4; root growth; germination

Abstract Auxin regulates a plethora of events during plant growth and development, acting in concert with other phytohormones. YUCCA genes encode flavin monooxygenases that function in tryptophan-dependent auxin biosynthesis. To understand the contribution of the YUCCA4 (YUC4) gene on auxin homeostasis, plant growth and interaction with abscisic acid (ABA) signaling, 35S::YUC4 seedlings were generated, which showed elongated hypocotyls with hyponastic leaves and changes in root system architecture that correlate with enhanced auxin responsive gene expression. Differential expression of PIN1, 2, 3 and 7 auxin transporters was detected in roots of YUC4 overexpressing seedlings compared to the wild-type: PIN1 was down-regulated whereas PIN2, PIN3 and PIN7 were up-regulated. Noteworthy, 35S::YUC4 lines showed enhanced sensitivity to ABA on seed germination and post-embryonic root growth, involving ABI4 transcription factor. The auxin reporter genes DR5::GUS, DR5::GFP and BA3::GUS further revealed that abscisic acid impairs auxin responses in 35S::YUC4 seedlings. Our results indicate that YUC4 overexpression influences several aspects of auxin homeostasis and reveal the critical roles of ABI4 during auxin-ABA interaction in germination and primary root growth.