Sugars promote graft union development in the heterograft of cucumber onto pumpkin  

作　　者：Li Miao Qing Li Tian-shu Sun Sen Chai Changlin Wang Longqiang Bai Mintao Sun Yansu Li Xing Qin Zhonghua Zhang Xianchang Yu 

机构地区：[1]Institute of Vegetables and Flowers,Chinese Academy of Agriculture Sciences,Beijing 100081,China [2]College of Horticulture,Qingdao Agricultural University,Qingdao 266109,China [3]College of Horticulture,Shanxi Agricultural University,Taigu,Jinzhong,Shanxi 030801,China

出　　处：《Horticulture Research》2021年第1期2198-2214,共17页园艺研究（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(No.31772363);the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS);the“Taishan Scholar”Foundation of the People’s Government of Shandong Province,the Key Laboratory of Horticultural Crop Biology and Germplasm Innovation,the Ministry of Agriculture,China;the Earmarked fund for Modern Agro-industry Technology Research System(CARS-25-C-01).

摘　　要：The use of heterografts is widely applied for the production of several important commercial crops,but the molecular mechanism of graft union formation remains poorly understood.Here,cucumber grafted onto pumpkin was used to study graft union development,and genome-wide tempo-spatial gene expression at the graft interface was comprehensively investigated.Histological analysis suggested that resumption of the rootstock growth occurred after both phloem and xylem reconnection,and the scion showed evident callus production compared with the rootstock 3 days after grafting.Consistently,transcriptome data revealed specific responses between the scion and rootstock in the expression of genes related to cambium development,the cell cycle,and sugar metabolism during both vascular reconnection and healing,indicating distinct mechanisms.Additionally,lower levels of sugars and significantly changed sugar enzyme activities at the graft junction were observed during vascular reconnection.Next,we found that the healing process of grafted etiolated seedlings was significantly delayed,and graft success,xylem reconnection,and the growth of grafted plants were enhanced by exogenous glucose.This demonstrates that graft union formation requires the correct sugar content.Furthermore,we also found that graft union formation was delayed with a lower energy charge by the target of rapamycin(TOR)inhibitor AZD-8055,and xylem reconnection and the growth of grafted plants were enhanced under AZD-8055 with exogenous glucose treatment.Taken together,our results reveal that sugars play a positive role in graft union formation by promoting the growth of cucumber/pumpkin and provide useful information for understanding graft union healing and the application of heterografting in the future.

关 键 词：HEALING METABOLISM UNION 

分 类 号：Q94[生物学—植物学] S642.2[农业科学—蔬菜学]