Cloning Of Apple Transcription Factor MdWRKY24 And Its Expression Analysis In Different Rootstock-scion Combination

The main trend of apple cultivation in the world is the dense planting and intensive cultivation of short stocks.The short stock orchards have the advantages of small crown width,high light utilization efficiency,early flowering and early fruit,good fruit quality,convenient management and high economic benefits.However,there are still many unclear aspects about the dwarfing mechanism of apple dwarf rootstocks so far.The application of dwarfing rootstocks does not match the research on dwarfing mechanism,which makes the application of molecular assisted breeding in the breeding process of dwarfing rootstocks greatly affected.limit.This experiment uses dwarf rootstocks M9 and SH40,and potted red Fuji apple trees with the arboriculture rootstock Barong Begonia as the intermediate stock.The key transcription factors are screened by transcription sequencing,and gene cloning and expression analysis are performed to illustrate the key transcription factors.The characteristics provide a reference for revealing the dwarfing mechanism of apple dwarfing rootstock.Below are key research findings are as follows:1.Transcriptome sequencing of the shoot tips and new shoot phloem of Fuji apple trees with different interstocks.A total of 460 differentially expressed transcription factors were obtained.Among them,M9 has 13 transcription factors that are significantly differentially expressed compared with M.robusta as an interstock.8 transcription factors are up-regulated and 5 transcription factors are down-regulated;SH40 and M.robusta are down-regulated.There are 45 transcription factors that are significantly differentially expressed compared to the interstock.9 transcription factors are up-regulated and 36 transcription factors are down-regulated.There are 57 transcription factors that are significantly differently expressed when SH40 and M9 are used as interstock.20 transcription factors are up-regulated and 37 transcription factors are down-regulated.There is a total of 1 gene that is differentially expressed in the comparison of the three test materials,which is named MdWRKY24.2.In the autumn shoot growth period,take the stem apex,new shoot phloem of 3 kinds of test materials,and perform qRT-PCR analysis.The test material with M9 as the intermediate anvil in the stem apex and new shoot phloem The expression level of MdWRKY24 gene was significantly higher than that of the other two samples,and the expression trend was consistent with the results of transcriptome sequencing.3.The CDs sequence of the MdWRKY24 gene is 657bp in length and encodes 218 amino acids by cloning.It contains the WRKYGQK domain and contains the C2H2 type zinc finger structure.It belongs to the second category of WRKY subfamily.The MdWRKY24 gene promoter was predicted,including abscisic acid,jasmonic acid,auxin-related cis-acting elements,and other 9 gene family 21 transcription factor binding sites.4.The analysis of the sequencing results showed that in the plant hormone synthesis and metabolism pathway,the two dwarf rootstocks M9 and SH40 were compared with the arboriculture rootstock,M.robusta,and a common and significantly expressed gene CYP707A1 was obtained;Pathway metabolism pathway has three common and significantly differentially expressed genes,IAA9,HA3 and SnKR2.10;and two other genes,LAX2,GID1C,are significantly differentially expressed compared with the M.robusta,but their differential gene expression patterns are different.Analyzing the promoters of significantly different genes related to hormones in the three test materials,two significantly differently expressed genes SnRK2.10 and CYP707A1 containing the W-box protein binding motif of MdWRKY24 gene were obtained.5.Take the new shoot tips of 3 kinds of test materials during the autumn shoot growth period to determine the hormone content regulated by genes that are differentially expressed in the hormone metabolism pathway.The ABA content in the dwarf rootstocks M9 and SH40 as the intermediate stocks is compared with the Fuji with Malus hupehensis Rehd as the base stock.The ABA content of the dwarf stocks is significantly higher than that of the arbor stocks,and the ABA content increases with the increase of the dwarfing ability of the tree.Gradually increase.The content of IAA and GA3 in the dwarf anvil test material was significantly lower than that of the arbor anvil test material,and increased with the increase of plant growth vigor.