Tang C.,Chinese Academy of Sciences |
Xiao X.,Chinese Academy of Sciences |
Xiao X.,Hainan University |
Li H.,Chinese Academy of Sciences |
And 6 more authors.
PLoS ONE | Year: 2013
Increasing demand for natural rubber prompts studies into the mechanisms governing the productivity of rubber tree (Hevea brasiliensis). It is very interesting to notice that a rubber tree of clone PR107 in Yunnan, China is reported to yield more than 20 times higher than the average rubber tree. This super-high-yielding (SHY) rubber tree (designated as SY107), produced 4.12 kg of latex (cytoplasm of rubber producing laticifers, containing about 30% of rubber) per tapping, more than 7-fold higher than that of the control. This rubber tree is therefore a good material to study how the rubber production is regulated at a molecular aspect. A comprehensive cDNA-AFLP transcript profiling was performed on the latex of SY107 and its average counterparts by using the 384 selective primer pairs for two restriction enzyme combinations (ApoI/MseI and TaqI/MseI). A total of 746 differentially expressed (DE) transcript-derived fragments (TDFs) were identified, of which the expression patterns of 453 TDFs were further confirmed by RT-PCR. These RT-PCR confirmed TDFs represented 352 non-redundant genes, of which 215 had known or partially known functions and were grouped into 10 functional categories. The top three largest categories were transcription and protein synthesis (representing 24.7% of the total genes), defense and stress (15.3%), and primary and secondary metabolism (14.0%). Detailed analysis of the DE-genes suggests notable characteristics of SHY phenotype in improved sucrose loading capability, rubber biosynthesis-preferred sugar utilization, enhanced general metabolism and timely stress alleviation. However, the SHY phenotype has little correlation with rubber-biosynthesis pathway genes. © 2013 Tang et al.
Li L.,Yunnan Tropical Crops Research Institute |
Liang G.-P.,Yunnan Tropical Crops Research Institute |
Guan Y.,Yunnan Tropical Crops Research Institute |
Huang F.-X.,Yunnan Tropical Crops Research Institute |
And 2 more authors.
Zhiwu Shengli Xuebao/Plant Physiology Journal | Year: 2012
Non-seedling somatic embryos of Hevea brasiliensis, including dicotyledonous embryo, connection radicle embryo, polycotyledonous embryo, monocotyledonous embryo and cotyledon recallus embryo, were used as explants in this study. The bud differentiation and the mini-juvenile-type bud stick cultivation of all these somatic embryos were studied. The results indicate that all 5 types of embryos can develop buds after they were cultured in an induction medium for 80 d. The highest differentiation rate was 90% found in dicotyledonous embryos, and the lowest differentiation rate was 20% found in monocotyledonous embryos. Polycotyledonous embryo and connection radicle embryo could differentiate 3 buds at most, 2 for dicotyledonous embryo. The optimal medium for the propagation of mini-juvenile-type bud stick was MS+6-BA 2 mg·L-1 or MS+6-BA 2 mg·L-1+KT 1 mg·L-1. The optimal basic medium for elongation of mini-juvenile-type bud stick was MS. With addition of NAA, the elongation of shoots can be inhibited.