MOLECULAR STUDY OF CBF AND WCOR14 GENES IN SELECTED SUGARCANE CULTIVARS AND ITS WILD RELATIVE SACCHARUM SPONTANEUM L.

Abstract

Abiotic factors severely affect, alter and limit the yield and quality of the plants. Among them, a significant stress to plant growth and quality is given by cold or low temperature. In order to minimize or localize the cold stress, plants adopt mechanisms in the form of elevated expression levels of cold responsive genes. In the present study, expression of cold responsive genes in sugarcane cultivars namely SPSG-394, CP-77400 and CP-851491 was performed along with expression analysis of these genes in wild sugarcane Saccharum spontaneum L. Expression of the stress responsive genes was detected through performing a cold stress experiment at 4°C for 0, 12 and 24 hours treatment. Tissues subsequent to stress treatment were collected and cryopreserved at -80C for RNA extraction. Quantification of expression levels of stress responsive genes namely CBF1, CBF2, CBF3 and WCOR14 was performed with the help of semi-quantitative RT-PCR (reverse transcriptase polymerase chain reaction). The results indicated that CBF1, CBF2 and CBF3 were abundantly expressed in all three sugarcane cultivars whereas their expression was higher in S. spontaneum L than in their commercial counterparts. Expression of the gene WCOR14 was seen to be higher in both commercial and sugarcane wild relative. Those amplified products were sequenced and then aligned using Basic Local Alignment Tool (BLAST) at NCBI, which demonstrated that genes CBF1, CBF3 and WCOR14 had conserved domains with other known stress-responsive genes like DREB and CO14. However, CBF2 encoded an uncharacterized protein and a conserved domain (gypsy type transposon). From all the above, we can conclude that the expression quantities of the stressresponsive genes were elevated in sugarcane cultivars SPSG-394 and CP-851491 exposed to cold stimuli and this factor could be contributive towards their ability to withstand higher cold stress.