Rubber latex is the blood that runs through the veins of Kerala’s economy. From acres of plantations to small groves in backyards, Hevea brasiliensis is tapped for its natural latex, with unique properties that can’t be matched by synthetic polymers. There have been many interventions to improve rubber productivity: budding, identifying clones for better yield and abiotic stress tolerance.
Research on the mechanism of rubber latex production led to the identification of the gene responsible for natural latex biosynthesis – HMGR. Scientists also report that high yielding rubber clones have a predominant expression of HMGR.
Image: Anoop Kumar V, S D College, Aluva
Taking a cue from this discovery about the correlation between rubber production and HMGR gene activity, scientists from the Rubber Research Institute of India, Kottayam; the Kerala Agricultural University, Thrissur, the Government Arts and Science College, Palakkad and the Periyar University of Tamil Nadu recently collaborated to develop a transgenic rubber plant with enhanced latex production.
The team used a plasmid vector for gene transformation. Ovules from immature fruit were used for callus initiation. The callus was subsequently infected with cultured Agrobacterium colonies. Finally, the team cultured both gene-transformed callus and untransformed callus in standard culture media under sterile conditions.
To evaluate the success of gene transformation, the team used a polymerase chain reaction to make many copies of the gene and other biotechnological tools to insert it into rubber plant tissue, grown in the lab.
Once sure that the gene was indeed present in the callus, the team initiated embryo induction and cultured the embryos into full plants. They transferred the transgenic rubber plants into potting media and used them for further investigations.
To evaluate the productivity of the transgenic rubber plant, the scientists tapped a six-year-old rubber tree in controlled greenhouse conditions. The yield from the transgenic rubber plant was 18-20% higher!
With more than 40 % success using somatic embryogenesis, many clones of the higher yielding variety can now be produced easily. Of course, field trials may need to be conducted before large-scale field planting. This is where scientifically oriented farmers reading this report play a critical role.
Plant Physio.Biochem. 127: 414-424 (2018)
S Suresh Ramanan
Sher-E-Kashmir University of Agricultural Sciences and Technology of Jammu