Abstract
There are three genes encoding for 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) in
Heavea brasiliensis
;
hmgr-1, hmgr-2
and
hmgr-3
. The
hmgr-1
is likely to be involved in rubber biosynthesis. In
this study, the diurnal variation and the relationship of
hmgr-1
mRNA levels with dry rubber content in
Heavea
brasiliensis
were investigated by using Northern blot analysis.
The semi-quantitative RT-PCR was also developed
to determine
hmgr-1
mRNA levels. The
hmgr-1
mRNA was found to vary with the tapping times and the peak of
mRNA was at 02:00 a.m. The
hmgr-1
mRNA showed positive correlation with dried rubber content {RRIM600
r=0.499 (p<0.05), BPM24 r=0.454 (p<0.05) and PB235 r=0.703 (p<0.01), respectively}. A strong correlation was
observed between
hmgr-1
expression using sqRT-PCR and Northern blot analysis with an R
2
value of 0.989
(p<0.001). These results supported that the
hmgr-1
gene play an important role in rubber biosynthesis pathway
and the optimized sqRT-PCR protocol was appropriated for determination of
hmgr-1
expression in latex of
Hevea
brasiliensis
.
Keywords :
gene expression; 3-hydroxy-3-methylglutaryl coenzyme A reductase
;
Hevea brasiliensis
