Self S‑RNase reduces the expression of two pollen‑specific COBRA genes to inhibit pollen tube growth in pear  

作　　者：Lei Wu Ying Xu Kaijie Qi Xueting Jiang Min He Yanbo Cui Jianping Bao Chao Gu Shaoling Zhang 

机构地区：[1]Centre of Pear Engineering Technology Research,State Key Laboratory of Crop Genetics and Germplasm Enhancement,Nanjing Agricultural University,Nanjing,Jiangsu,China [2]College of Life Sciences,Nanjing Agricultural University,Nanjing,Jiangsu,China [3]Nanjing Ningcui Biological Seed Company Limited,Nanjing,Jiangsu,China [4]College of Plant Science,Tarim University,Alaer,Xinjiang 843300,China

出　　处：《Molecular Horticulture》2023年第1期39-50,共12页分子园艺（英文）

基　　金：Open access funding provided by Shanghai Jiao Tong University;supported by the Natural Science Foundation of China(32172511);the National Key Research and Development Program of China(2022YFD1200501);the Nanjing Agricultural Science and Technology Industry-University-Research Collaboration Project(2022RHCXY);the Earmarked Fund for the China Agriculture Research System(CARS-28).

摘　　要：Due to self-incompatibility(SI)prevents self-fertilization,natural or artificial cross-pollination has been conducted in many orchards to stabilize fruit yield.However,it is still puzzled which routes of self S-RNase arresting pollen tube growth.Herein,17 COBRA genes were isolated from pear genome.Of these genes,the pollen-specifically expressed PbCOB.A.1 and PbCOB.A.2 positively mediates pollen tube growth.The promoters of PbCOB.A.1 and/or PbCOB.A.2 were bound and activated by PbABF.E.2(an ABRE-binding factor)and PbC2H2.K16.2(a C2H2-type zinc finger protein).Notably,the expressions of PbCOB.A.1,PbCOB.A.2,and PbC2H2.K16.2 were repressed by self S-RNase,suggesting that self S-RNase reduces the expression of PbCOB.A.1 and PbCOB.A.2 by decreasing the expression of their upstream factors,such as PbC2H2.K16.2,to arrest pollen tube growth.PbCOB.A.1 or PbCOB.A.2 accelerates the growth of pollen tubes treated by self S-RNase,but can hardly affect level of reactive oxygen species and deploymerization of actin cytoskeleton in pollen tubes and cannot physically interact with any reported proteins involved in SI.These results indicate that PbCOB.A.1 and PbCOB.A.2 may not relieve S-RNase toxicity in incompatible pollen tube.The information provides a new route to elucidate the arresting pollen tube growth during SI reaction.

关 键 词：PYRUS SELF-INCOMPATIBILITY COBRA C2H2-type zinc finger protein Pollen tube growth S-RNASE 

分 类 号：Q94[生物学—植物学]