Abstract:

Full-length DNA, cDNA and promoter sequences of nodulin-like gene have been isolated and characterized by isocaudarner inverse PCR (Ⅱ-PCR) and rapid isolating cDNA 5'' unknown sequence and promoter (RICUP) methods from cotton. Sequence analysis indicated that nodulin-like gene was 2 353 bp in size, including five introns and six exons. Its full-length cDNA was 1 480 bp, containing an 1 125-bp ORF structure, which encoded a 40.23-kD polypeptide with predicted isoelectric point of 8.433. A check against nr database in GenBank indicated that no DNA sequence was found to share homology with it. Searched in EST database, a 733-bp EST sequence of Gossypium arboreum L. (GenBank asscession number BF271235) was found to share 92% homology with it. Promoter of nodulin-like gene was 1 969 bp in length with several typical sequences, such as initiator, TATA box, CAAT-like box and AT-rich sequence. Southern blotting analysis suggested that one copy of nodulin-like gene was integrated into cotton genome. Northern blotting analysis showed that nodulin-like gene expressed preferentialy in fiber and reproductive organs of cotton, such as bud, flower and boll. Our work provides researchers with candidate genes to improve agronmic traits of cotton and also provide efficient expression elements for problem solving in transgenic Bt cotton, namely resistance to bollworm declining dramatically at late developmental stage of cotton.

Key words: nodulin-like gene, promoter, structural characteristic, genetic expression, cotton