Auxin Regulates Sucrose Transport to Repress Petal Abscission in Rose (Rosa hybrida). Issue 11 (25th August 2020)

• Record Type: Journal Article
• Authors: Liang, Yue; Jiang, Chuyan; Liu, Yang; Gao, Yuerong; Lu, Jingyun; Aiwaili, Palinuer; Fei, Zhangjun; Jiang, Cai-Zhong; Hong, Bo; Ma, Chao; Gao, Junping
• Is Part Of: The Plant Cell. Volume 32:Issue 11(2020)
• Page Start: 3485
• Page End: 3499
• Publication Date: 2020-08-25
• DOI: 10.1105/tpc.19.00695
• Languages: English
• ISSNs: 1040-4651

Abstract

Abstract : Auxin modulates sucrose transport to repress petal abscission in rose, and this process is regulated by a Rh ARF7- Rh SUC2 module in the abscission zone. Abstract: Developmental transitions in plants require adequate carbon resources, and organ abscission often occurs due to competition for carbohydrates/assimilates. Physiological studies have indicated that organ abscission may be activated by Suc deprivation; however, an underlying regulatory mechanism that links Suc transport to organ shedding has yet to be identified. Here, we report that transport of Suc and the phytohormone auxin to petals through the phloem of the abscission zone (AZ) decreases during petal abscission in rose ( Rosa hybrida ), and that auxin regulates Suc transport into the petals. Expression of the Suc transporter Rh SUC2 decreased in the AZ during rose petal abscission. Similarly, silencing of Rh SUC2 reduced the Suc content in the petals and promotes petal abscission. We established that the auxin signaling protein Rh ARF7 binds to the promoter of Rh SUC2, and that silencing of Rh ARF7 reduces petal Suc contents and promotes petal abscission. Overexpression of Rh SUC2 in the petal AZ restored accelerated petal abscission caused by Rh ARF7 silencing. Moreover, treatment of rose petals with auxin and Suc delayed ethylene-induced abscission, whereas silencing of Rh ARF7 and Rh SUC2 accelerated ethylene-induced petal abscission. Our results demonstrate that auxin modulates Suc transport during petal abscission, and that this process is regulated by a Rh ARF7- Rh SUC2 module in the AZ.