Arabidopsis DNA topoisomerase I alpha is required for adaptive response to light and flower development

作者：Kupriyanova Evgenia V^*; Albert Evgeniy V; Bliznina Aleksandra I; Mamoshina Polina O; Ezhova Tatiana A

来源：Biology Open, 2017, 6(6): 832-843.

DOI：10.1242/bio.024422

• DNA topoisomerase
• Light response
• Shade avoidance
• Floral morphogenesis
• RNA sequencing

DNA topoisomerase I alpha (TOP1 alpha) plays a specific role in Arabidopsis thaliana development and is required for stem cell regulation in shoot and floral meristems. Recently, a new role independent of meristem functioning has been described for TOP1 alpha, namely flowering time regulation. The same feature had been detected by us earlier for fas5, a mutant allele of TOP1 alpha. In this study we clarify the effects of fas5 on bolting initiation and analyze the molecular basis of its role on flowering time regulation. We show that fas5 mutation leads to a constitutive shade avoidance syndrome, accompanied by leaf hyponasty, petiole elongation, lighter leaf color and early bolting. Other alleles of TOP1 alpha demonstrate the same shade avoidance response. RNA sequencing confirmed the activation of shade avoidance gene pathways in fas5 mutant plants. It also revealed the repression of many genes controlling floral meristem identity and organ morphogenesis. Our research further expands the knowledge of TOP1 alpha function in plant development and reveals that besides stem cell maintenance TOP1 alpha plays an important new role in regulating the adaptive plant response to light stimulus and flower development.

• 出版日期2017-6-15