Identification And Expression Analysis Of Aux/IAA Gene Family In Capsicum Annuum L.

The pepper derived from Mexico,which has a unique flavor because of capsaicin and vitamins.It is one of the vegetables that humans like eating.According to incomplete statistics,peppers have a cultivation area of 20 million in China,and the output is 28 million tons.peppers have gradually become an important source of income for farmers,so the area is still expanding.Auxin has an extremely complex mechanism of action.At present,breakthroughs have been made in the study of gene transcriptional expression related to auxin regulation.the transcriptional repressor protein Aux/IAA plays a key role in the auxin signal transduction pathway.However,there are few reports on the pepper Aux/IAA gene family.In this paper,the members of Aux/IAA gene family of pepper were identified by bioinformatics method,and their evolutionary relationships,chromosomal location,gene structure and tissue expression patterns were analyzed.The expression trend of Aux/IAA gene family was detected by qRT-PCR,including pulp,seeds and placenta in fruit;abscisic acid ABA,jasmonic acid JA,gibberellic acid GA3,high temperature and low temperature stress in leaves.The main findings are as follows:1.A total of 22 pepper Aux/IAA gene family members were identified from the Zunla-1 genome using Pfam and HMMER online software,which can be divided into7 groups: A,B,C,D,E,F and G.Only 7 of all the chromosomes of the pepper distributed these genes,and the third chromosome was the most with 4 and 3 gene forming gene clusters at the upper and lower ends.These genes all contain introns,and each contains different introns;generally the structure of Aux/IAA genes in the same group is very similar.Among the 22 Aux/IAA protein sequences of pepper,16 contained 4 intact domains with 1 to 5 introns,and 6 sequence lost introns.The structure was relatively simple.2.Using Tophat and Cufflink software analyzes the expression pattern of pepper Aux/IAA gene family members in tissues and organs.The results suggested that 10 of the 22 genes were detected in all tissues of pepper,showing a distinct constitutive expression pattern;9 genes were detected only in individual tissues,showing a obvious specific expression pattern;The remaining genes are not expressed.Eight genes were selected to analyzes the expression pattern of fruit.The results showed that the relative expression of Capana03g004568 and Capana03g000244 in the flesh and placenta continued to decrease.The trend of Capana03g000310 was opposite tothe former two;Capana03g003343 and Capana06g001308 were relative in Capricorn and seed.The expression level tends to 0,and it rises first and falls in the flesh,and the relative expression level is 0 in the late stage of fruit development.Capana00g000845 is continuously expressed in seeds and is not significantly expressed in pulp and placenta.Capana09g001096 has a relatively high relative expression in pulp,placenta and seeds,and it has a uniform change in the relative expression of these three tissues during pollination for 10-50 days.The relative expression of Capana03g004455 in pulp,seeds and placenta showed a downward trend.3.qRT-PCR was used to analyze the expression of Aux/IAA representative genes in abscisic acid ABA,jasmonic acid JA,gibberellin GA3 and high temperature and low temperature stress.The results showed that Capana00g002644 was positively induced by abscisic acid and jasmonic acid stress;Capana00g002644 and Capana01g001423 were positively induced by gibberellin stress;Capana00g002644,Capana03g003343 and Capana03g000311 were positively induced by low temperature stress,and Capana00g002644 and Capana07g000391 were positively induced by high temperature stress.These genes that are positively induced by hormones or temperature are likely to play an important regulatory role in the plant's resistance to corresponding abiotic stresses.