LEA5 gene was postulated related with both stress and hormone responses. In an attempt to find genes exclusively expressed during fruit ripening of Cara Cara navel orange, a novel cDNA clone encoding late embryogenesis-abundant protein 5 like gene (CitLEA5-1) was obtained. It was 582 bp in length, containing 97 deduced amino acids. Compared with the stress-induced LEA5 from leaves of Citrus sinensis, CitLEA5-1 had a shorter 3′ untranslated region (UTR). Semi- quantitative RT-PCR analysis revealed that CitLEA5-1 was transcriptional regulated during fruit ripening of Cara Cara navel orange.
Abundance of simple sequence repeat (SSR) in Citrus sequences from EMBL database was investigated by usingcomputer program MISA (MIcroSAtellite), which aimed to provide useful information for the development of SSR markers.Among 32 896 sequences of Citrus, 4 987 SSRs were found in 4 167 sequences and the average distance between SSRs wasapproximately 3.5 kb. Mononucleotide repeats (50.6%) were the most abundant repeats. And di-, tri-, tetra-, penta- andhexa-nucleotide repeats were 22.8, 25.2, 1, 0.08, and 0.36%, respectively. The most abundant motif was A/T followed indescending order by AG/CT, AC/GT, AT/TA. AAT/ATT, AAG/CTT, AGC/CGT, ACG/CTG and C/G. They comprised about90% of all microsatellites. Ten primer pairs were designed, and three of them produced clear visible bands among Citrusand its related genera.
