Tuesday, 2 April 2013

Hunting genes for C4 rice

IRRI Seminar

By Govinda Rizal
Postdoctoral fellow
C4 Rice Project, IRRI

1315-1415 H, Thursday, 11 April 2013
Havener Auditorium, IRRI


In higher plants, the first intermediate product of photosynthesis (CO2 fixation) is either phosphoglycerate (a 3-carbon compound) or oxaloacetate (a 4-carbon compound). This is the basis for grouping plant species as C3 or C4. 

C4 plants photosynthesize more efficiently than C3 plants, especially under higher temperature. The advantage of C4 over C3 species are due mainly to compartmentalized “Kranz” leaf anatomy, low CO2 compensation point, and reduced photorespiration.

Under the C4 Rice Project, Govinda's team is working towards engineering the C4 photosynthesis system into rice, a C3 species. To genetically engineer C4 photosynthesis in rice, the genes and regulatory elements that cause and support the modification and associated optimization must be identified.

Genetic factors for most of the basic traits remain unidentified. To unearth these factors, C4 plants were mutagenized and screened for causal genes. The methods involved initial seed mutation, growing a million mutant plants to generate an M2 population, screening for a desired phenotype, back-crossing candidate mutants, sequencing, and, finally, identification of the causal nucleotide changes.

In the presentation, Govinda will reveal progress made towards these goals.


  1. When will you be able to develop a C4 rice? or when will it be released?

  2. John Sheehy, former head, Applied Photosynthesis and Systems Modeling Laboratory (1995-2009) at the International Rice Research Institute discusses in an interview IRRI's C4 rice project in the attempt to increase rice yield by 50%. This interview was conducted on 26 March 2013. Find it on YouTube at http://youtu.be/b2IYNZu6SpY