Sweet Sorghum (Sorghum bicolor L.) Cloning and Functional Analysis of Callose Gene SbGlu1 in Protein Content

The Sweet sorghum ( Sorghum bicolor L.) Moench is a variant of grain sorghum, which origins in Africa. Due to its high sugar and tolerance, it has been considered as a potentially useful energy crop and received more attention. However, less study on sweet sorghum has been performed in physiology and molecular by Al stress. These results illustrated that the decrease of β-1,3-glucanase activity by Al could lead to callose accumulation. In POTCHETSTRM, five β-1,3-glucanase genes expression were up-regulated, and a gene expression was down-regulated. In ROMA, only one β-1,3-glucanase gene, SbGlu1 ( Sb03g045630.1 ) expressed response to Al, and the expression was higher in ROMA than in POTCHETSTRM. The expression levels of six callose synthase-like genes were very low exposure of 10 µM Al upon to 24 h in ROMA, but POTCHETSTRM exhibited the highest expression level only at 24 h. Therefore, callose synthase-like genes maybe regulate callose deposition in the later stage of Al stress in sweet sorghum. The SbGlu1 expression positively correlated with callose content in both cultivars. The SbGlu1 expression maybe involve in callose degradation in sweet sorghum by Al stress. The full-length cDNAs of SbGlu1 were cloned from the root tips of both ROMA and POTCHETSTRM, respectively. The SbGlu1 were transient expressed in onion epidermal cells for subcellular localization, showed that SbGLU1 is soluble with no specificity localization.