Scientists Develop High-Yield Dwarf Plants
Gurmukh S. Johal assistant professor of botany and plant pathology at Purdue, USA

EUR522 10/03/2003
Text: Researchers Discover Mechanism that Generates Dwarfed Crop Plants
(Findings could improve food production in developing countries) (1710)

A research team at Purdue University has uncovered the genetic mechanism that prevents certain crop plants from growing tall ---- a finding that could improve food production in certain regions of the world.

Gurmukh S. Johal, assistant professor of botany and plant pathology, and Dilbag Multani at Pioneer Hi-Bred International, have identified the process that generates dwarfed corn and sorghum plants, which grow to roughly half the height of their normal counterparts. This discovery may help in the development of dwarf forms in other crops, which hold the potential to improve food production in certain regions of the world.

"Dwarf plants put more of their energy into producing grains, instead of growing tall," said Guri Johal, assistant professor of botany and plant pathology at Purdue. That means farmers can apply fertilizers to crops with the intent of increasing yield without the worry that plants will grow so tall they topple over from wind, rain or even their own weight

An October 2 press release says the scientists, whose findings are reported in the latest issue of the journal Science, identified the process that generates dwarfed corn and sorghum plants, which grow to roughly half the height of their normal counterparts. The study also revealed the genetic process behind an unstable variety of sorghum frequently used in commercial production. .

Dwarf varieties of rice and wheat, introduced during the 1960s throughout the Indian subcontinent and Southeast Asia, were largely responsible for thwarting famine in those regions.

Johal and his colleagues found that loss of a gene product called a p-glycoprotein generates these dwarf corn and sorghum plants by interfering with the movement of auxin, an essential hormone in plant growth and development.

A dwarf form of corn called brachytic2 (br2) was recognized in 1951, but until now scientists have not understood the genetic mechanism underlying the plant's mutation. Unlike dwarf sorghum, however, dwarf corn has not been put into commercial use partly because corn hybrids grown in the United States are not excessively tall.

However, Johal said the discovery of the dwarfing mechanism may renew interest in developing a dwarf corn with improved yield, which could be of particular interest in developing countries. Johal also said that sorghum may be crucial to the future impact of the "green revolution."

"The next round of the green revolution must impact Africa. Sorghum, which is a staple in many parts of Africa, especially sub-Saharan Africa, could play a key role there," he said.

Other cereal crops, including teff, a grain grown primarily in Ethiopia, and basmati rice, grown in India, which both grow unusually tall, also may benefit from the discovery reported in this study

Gurmukh (Guri) Johal
Purdue University
Botany and Plant Pathology, Lilly Hall
915 West State Street
West Lafayette, IN 47907-2054
Office:  Lilly G-317
Phone: (765) 494-4448
FAX:      (765) 494-0363

Education

M.S., Punjab Agricultural University, India - Genetics
Ph.D., Simon Fraser University, B.C., Canada - Plant Pathology

Background

June 2002 – present
Assistant Professor of Plant Pathology, Department of Botany and Plant Pathology, Purdue University.

March 1998 – June 2001
Senior Research Scientist, Disease Resistance Group, Pioneer Hi-Bred International Inc.

March 1993 – February 1999
Assistant Professor of Maize Genetics, Department of Agronomy, University of Missouri

Selected Publications

Gray, J., D. Janick-Buckner, B. Buckner, P. Close, and G.S. Johal. 2002. Light-dependent death of maize lls1 cells is mediated by functional chloroplasts. Plant Physiology. Accepted.

Nadimpalli R., N. Yalpani, G.S. Johal, and C.R. Simmons. 2000. Prohibitins, stomatins, and plant disease response genes compose a protein superfamily that controls cell proliferation, ion channel regulation and death. J. Biological Chemistry 275: 29579-29586.

Buckner, B., D. Janick-Buckner and G.S. Johal. 2000. Cell death in maize. Physiologia Plantarum 108: 231-239.

Hu, G., N. Yalpani, S.P. Briggs and G.S. Johal. 1998. A porphyrin pathway impairment is responsible for the phenotype of a dominant disease lesion mimic mutant of maize. Plant Cell 10: 1095-1105.

Buckner, B., D. Janick-Buckner, J. Gray and G.S. Johal. 1998. Cell death mechanisms in maize. Trends in Plant Science 3: 218-223.

Multani, D.S., R.B. Meeley, A.H. Paterson, J. Gray, S.P. Briggs and G.S. Johal. 1998. Plant-pathogen micro evolution: Molecular basis for the origin of a fungal disease in maize. Proceedings of the National Academy of Sciences U.S.A. 95: 1686-1691.

Gray, J., P.S. Close, S.P. Briggs and G.S. Johal. 1997. A novel suppressor of cell death in plants encoded by the Lls1 gene of maize. Cell 89: 25-31.

Johal, G.S., S. Hulbert and S.P. Briggs. 1995. Disease lesion mimic of maize: a model for cell death in plants. BioEssays 17: 685-692.

Johal, G.S., J. Gray, D. Gruis and S.P. Briggs. 1995. Convergent insights into mechanisms determining disease and resistance responses in plant-fungal interactions. Canadian J. of Botany 73S: 468-474.

Briggs, S.P. and Johal, G.S. 1994. Genetic patterns of host-pathogen interactions. Trends in Genetics 10: 12-16.

Johal, G.S. and S.P. Briggs. 1992. Reductase activity encoded by the HM1 disease resistance gene in maize. Science