Certain problems have been hampering the development and growth of root crops industry in the country. These problems include the high perishability of cassava, acridity and pest in taro, and pest and diseases of sweet potato, cassava and yam.

To address these problems, Dr. Edgardo E. Tulin and Ms. Zenaida T. Ecleo of the Leyte State University conducted the research “Differential display protein profiling of some common production and post-production problems in root crops.”

Protein expression profiling is a technique that gives researchers an accurate picture of the proteins present in a cell at any given time. The technique, researchers explained, is a powerful tool for discovering proteins associated with the biochemical state of a sample in response to certain stimuli.

Discovering such “signature” proteins are useful for diagnostic purposes and in applying appropriate interventions to problems on production and postproduction of root crops.

The researchers were able to establish 9 expression profiles for acrid and non-acrid taro corms; fresh and stored cassava roots; spider mite- and scale insect-infested and non-infested cassava; two profiles for different varieties of blight-infested taro; healthy and anthracnose-infected yam leaves; two profiles for sweet potato leaves infested with scab and feathery mottle virus; and purple and white varieties of yam tubers.

Several differentially expressed specific proteins were identified as biochemical markers. From the profiles established, eight novel protein biochemical markers were identified.

This information can be used in isolating and cloning the gene for a more detailed characterization and functional evaluation. Further, the biochemical markers identified in this work can also be applied in the diagnoses and genetic manipulation of root crops to improve their traits and properties, in screening and selecting desirable traits, and seed certification for producing disease-free planting materials.

The study is the first report of such biochemical markers for acridity in taro, anthracnose infection in yam, blight infestation in taro, and in spider mite- and scale insect- infested cassava.

This study was chosen as the best (1st place) research paper at the National Symposium on Agriculture and Resources Research and Development held by PCARRD last 10 November 2006.