Abstract:

【Objective】 Cloning a defender against apoptotic cell death gene, GhDAD1, and analyzing its expression model could provide a theoretical foundation for both molecular mechanism research of apoptosis and breeding senescence-resistant varieties in shorted-season Gossypium hirsutum. 【Method】 RT-PCR and in silico cloning were used to amplify DNA sequence and full-length cDNA sequence of GhDAD1 in Gossypium hirsutum. Bioinformatics characterization of GhDAD1 had also been analyzed through all kinds of software. FISH was used to get the location of GhDAD1 on chromosomes. Both the expression patterns of GhDAD1 under the nature decrepitude and treatment of 6-BA, ethylene, H2O2, SA, NO were analyzed by real-time PCR. 【Result】 The length of GhDAD1 sequence is 866 bp, including a 354 bp ORF, 232 bp 5′-UTR, 280 bp 3′-UTR, five extrons and 4 introns. It was in conformity with the principles of Kozark and GT-AG. Homology analysis showed that the GhDAD1 was highly homologous to other DAD1 from different species, especially from Populus davidiana, Citrus unshiu (91%) and Arabidopsis thaliana (88%) other than barley and rice. GhDAD1 protein had 112 amino acids, and its pI was 8.32. The GhDAD1 gene was located on the long arm of the chromosomes. Real-time PCR showed that GhDAD1 gene expressed in all issues of Gossypium hirsutum, with flower and embryo having high expressing level. And the expressing level was on the decline with the processing of decrepitude. The CCRI10 was cultured by addition of 6-BA, ethylene, SA, NO, and H2O2. At the same time, chlorophyll was measured. The result of qRT-PCR showed that 6-BA and SA could retard the senescence, and the transcript of GhDAD1 was higher. The ethylene could accelerate the senescence, so the transcript of GhDAD1 was lower. The influence of H2O2 was not apparent. With the increasing of NO concentration, the expression level of GhDAD1 increased to a peak then decreased. 【Conclusion】 There seemed to be a gene about the defender against apoptotic cell death 1 in Gossypium hirsutum.

Key words: Gossypium hirsutum, defender against apoptotic cell death factor, bioinformatics, expression model