Cloning And Functional Analysis Of Histone Acetylase Gene(SlHAG14) In Tomato(Solanum Lycopersicum)

Histone acetylation is a reversible process carried out by two classes of enzymes known as histone acetylases?HATs?and histone deacetylases?HDACs?acting on the ?-amino group of lysine residues in histones.Plant HATs are currently categorized into four groups on the basis of homology with other eukaryotic HATs and domain composition:?i?HAG with Acetyltransf₁ domain?PF00583??AT1?include GCN5-,ELP3-,HAT1-like acetyltransferases;?ii?HAM with a MYST?MOZ-YBF2/SAS3-SAS2-TIP60?domain;?iii?HAC with similarity to p300/CREB-binding protein;?iv?HAF related to the TATA binding protein-associated factor?TAFII250?family.The Arabidopsis genome was predicted to encode three HAGs,At HAG1,At HAG2 and At HAG3,which belong to GCN5,HAT1 and ELP3 families,respectively.ELP3 is the catalytic subunit,harboring a C-terminal histone acetyltranferase?HAT?domain and an N-terminal cysteine-rich motif that resembles an ironsulfur?Fe-S?radical S-adenosylmethionine?SAM?domain.ELP3 alone has intrinsic HAT activity and is capable of acetylating all four histones,whereas the six-subunit holo-Elongator predominantly acetylates lysine-14 of histone H3 and lysine-8 of histone H4.At HAG3/ At ELP3 is a member of the conserved Elongator HAT complex that interacts with RNA Pol II during transcript elongation and plays a role in cell proliferation during organ growth.Furthermore,At HAG3 can regulate plant response to ABA,oxidative stress resistance,and anthocyanin biosynthesis.Arabidopsis Elongator also regulates the auxin signaling gene SHY2/IAA3,the auxin influx carrier LAX2,ethylene signaling,jasmonic acid signaling,and abiotic stress.In addition,RNAi lines of At HAG3 are resistant to Agrobacterium-mediated transformation.The tomato genome encodes 26 proteins showing similarity to the HAG group.Given the wide range of expression values,the tomato HAGs in three groups of low,middle and high expression.In tomato,the closest homologs of At HAG1/At GCN5,At HAG3 and At MCC1 are SlHAG1,SlHAG14 and SlHAG12,respectively.At HAG3 is involved in transcription elongation,cell proliferation,leaf axis development,seedling and root growth,and At MCC1 was shown to be involved in flowering time and meiosis?The involvement of At HAG3?ELP3?in ABA responses in Arabidopsis is reported.In this paper,we used a bioinformatics qualitative analysis to obtain a tomato transcription factor SlHAG14?Solyc03g110910?gene.The protein?SlHAG14?is located in the tomato histone acetyltransferase?HATs?HAGs family of class B,and ELP3 is involved in the histone acetyltransferase extension subunit-mediated transcriptional extension process.Tomato SlHAG14 has high homology with Arabidopsis thaliana acetyltransferase gene AtHAG3.The specificity of tissue expression pattern was predicted by qRT-PCR and the correlation between multiple hormone-related and abiotic stress correlations of the seedlings of the gene?T1 generation?was combined with the physiological and biochemical indexes under the relevant phenotype.The The In the study,we can see that the expression of SlHAG14 gene in different tissues and developmental stages of wild-type tomato is specific in fruit.Using RNAi technique,we constructed the silencing vector of SlHAG14 gene,and then transformed the tomato transgenic plants by positive reaction of Agrobacterium tumefaciens and positive screening and identification.The expression of SlHAG14 gene in transgenic tomato positive plants was identified by RT-qPCR.We selected RNAi-1,RNAi-5 and RNAi-10?about 80-85%?with the best silencing efficiency in the follow-up experiment.The results of this study show that the silting Sl HAG14 gene enhances the total carotenoid content of tomato fruit.Tissue expression pattern analysis showed that SlHAG14 gene may be involved in the fruit ripening process;and silencing SlHAG14 gene expression was induced by ethylene.At present,the expression of SlHAG14 gene was inhibited by transgenic?T1 generation?seedlings and ABA sensitivity at high concentration,indicating that SlHAG14 gene may be involved in ABA response.The sensitivity of tomato transgenic?T1 generation?seedlings and hormones?GA3,MeJA?and salt stress was relatively insignificant.In the study,we can see some of the biological functions of tomato SlHAG14 gene,and further research is needed to make a comprehensive conclusion on the biological function of tomato SlHAG14 gene.