Author
CHANDRA, AMARESH - Indian Institute Of Sugarcane Research | |
VERMA, P - Collaborator | |
ISLAM, M - Collaborator | |
Grisham, Michael | |
JAIN, R - Indian Institute Of Sugarcane Research | |
SHARMA, A - Indian Institute Of Sugarcane Research | |
ROOPENDRA, K - Indian Institute Of Sugarcane Research | |
SINGH, K - Collaborator | |
SINGH, P - Indian Institute Of Sugarcane Research | |
VERMA, I - Indian Institute Of Sugarcane Research | |
SOLOMON, S - Indian Institute Of Sugarcane Research |
Submitted to: Plant Biology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/3/2014 Publication Date: 5/1/2015 Citation: Chandra, A., Verma, P.K., Islam, M.N., Grisham, M.P., Jain, R., Sharma, A., Roopendra, K., Singh, K., Singh, P., Verma, I., Solomon, S. 2015. Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage. Plant Biology. 17(3):608-617. DOI: 10.1111/plb.12276 Interpretive Summary: Some varieties of sugarcane begin producing sucrose in their stalks earlier in the season than in others. These are referred to as early sugar varieties, while those that accumulate sucrose later in the season are referred to as late sugar varieties. The process of a sugarcane plant producing sucrose is complex. Enzymes produced by the plant control parts of this process. This study compared the enzyme levels of an early sugar variety and a late sugar variety. Differences were observed in the levels of four enzymes known to be part of the sucrose production process at different times during the growing season. These results are important in helping scientists understand this complex process of sucrose production. Technical Abstract: Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose-phosphate synthase (SPS), soluble acid (SAI) and cell-wall invertase (CWI) are important. Expression of these enzymes was compared in an early (CoJ64) and late (BO91) maturing sugarcane variety using end-point and quantitative real-time PCR. Quantitative real-time PCR carried out at four crop stages revealed high CWI expression in upper internodes of CoJ64 which declined significantly in both top and bottom internodes with maturity. In BO91, CWI expression was high in both top and bottom internodes and declined significantly only in top internodes as crop matures. Overall, CWI expression was higher in CoJ64 than in BO91. With crop growth, no significant change in SPS expression in bottom internodes was observed in CoJ64; whereas in BO91, it decreased significantly. Barring a significant decrease in expression of SuSy in matured bottom internodes of BO91, no significant change was observed. Similar SAI expression was observed with both end-point and real-time PCR analyses except for a significant increased expression in top internodes of CoJ64 with maturity. SAI being a major sucrose-hydrolyzing enzyme, end-point PCR expression levels were also monitored in various internodal tissues of CoJ64 and BO91 and results indicated higher expression of SAI gene in BO91 at early crop stage. Enzyme inhibitors such as manganese chloride (Mn++), significantly suppressed expression of SAI in both early and late maturing varieties. Present findings enhance our understanding of critical sucrose metabolism gene expression in sugarcane varieties differing in content and time of peak sucrose storage. Thus, employing these genes synergistically, improvement of sugarcane for sucrose is possible. |