Physiological and molecular mechanisms of cytokinin involvement in nitrate-mediated adventitious root formation in apples  

作　　者：Muhammad Mobeen Tahir Li Fan Zhimin Liu Humayun Raza Usman Aziz Asad Shehzaib Shaohuan Li Yinnan He Yicen Lu Xiaoying Ren Dong Zhang Jiangping Mao 

机构地区：[1]College of Horticulture,Yangling Sub-Center of National Center for Apple Improvement,Northwest A&F University,Yangling 712100,China [2]Department of Plant Breeding and Genetics,Faculty of Agriculture and Environment,The Islamia University of Bahawalpur,Bahawalpur 63100,The Islamic Republic of Pakistan [3]National Cotton Breeding Institute,The Islamia University of Bahawalpur,Bahawalpur 63100,The Islamic Republic of Pakistan

出　　处：《Journal of Integrative Agriculture》2024年第12期4046-4057,共12页农业科学学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(32372675,32372657,32102359);the National Key Research and Development Project,China(2023YFD2301002);the Young Talent Fund of Association for Science and Technology in Shaanxi,China(20240218);the Science and Technology Major Project of Xinjiang Production and Construction Corps,China(2023AB077);the Chinese Universities Scientific Fund(2452023005);the China Apple Research System(CARS-27);the Cyrus Tang Foundation;the Fundamental Research Funds for the Central Universities,China。

摘　　要：Potassium nitrate(KNO_(3))promotes adventitious root(AR)formation in apple stem cuttings.However,evidence for the possible involvement of cytokinin(CK)in KNO_(3)-mediated AR formation in apples is still lacking.In this study,we cultured GL-3 apple microshoots in different treatment combinations.While the T1(KNO_(3)9.4 mmol L^(-1)+6-benzyl adenine(6-BA)2.22μmol L^(-1))and T3(6-BA 2.22μmol L^(-1))treatments completely inhibited AR formation,the control,T2(KNO_(3)9.4 mmol L^(-1)),and T4(KNO_(3)9.4 mmol L^(-1)+lovastatin(Lov)1.24μmol L^(-1))treatments developed ARs.However,T4-treated microshoots developed fewer and shorter ARs,indicating that optimum CK synthesis is needed for normal AR growth.This also suggests that these fewer and shorter ARs developed because of the presence of KNO_(3) in the same medium.The anatomy of the stem basal part indicated that the inhibition of CK biosynthesis delayed AR primordia formation.The endogenous levels of indole-3-acetic acid(IAA)and zeatin riboside(ZR)were higher in T2-treated microshoots,while the abscisic acid(ABA),gibberellic acid 3(GA_(3)),and brassinosteroid(BR)levels were higher in T4-treated microshoots.The expression levels of MdNRT1.1and MdNRT2.1 were higher in T2-treated microshoots at 3 and 8 days,while MdRR2 and MdCKX5 were higher at 8 and 16 days,respectively.Furthermore,higher IAA levels increased MdWOX11 expression,which in turn increased MdLBD16 and MdLBD29 expression in response to T2.The combined expression of these genes stimulated adventitious rooting by upregulating cell cycle-related genes(MdCYCD1;1 and MdCYCD3;1)in response to T2 treatment.This study shows that specific genes and hormonal pathways contribute to KNO_(3)-CK-mediated adventitious rooting in apples.

关 键 词：adventitious root(AR) cytokinin(CK) potassium nitrate(KNO_(3)) CROSSTALK HORMONES gene expression 

分 类 号：S661.1[农业科学—果树学]