RESEARCHERS at the Indian Institute of Science Education and Research (IISER) Bhopal, have identified a key gene in plants that encodes a protein that regulates the development of a seed into a sapling. The researchers have reported the nature of this gene and associated protein and their role in early seedling development in the journal Plant Physiology. According to the team, germination of a seed is a complex process involving many biochemical, physiological and morphological changes within the seedling in response to appropriate environmental conditions including moisture, temperature, air and light.

 

In many plants, one of the first steps in germination is the opening of the first embryonic leaves called cotyledons. The cotyledons protect the tender shoot that will develop into the aerial parts of the plant and the timing of its opening is crucial. “Unfavourable conditions such as untimely rainfall can lead to premature opening of the cotyledon, which can result in damage to the shoot and failure of the plant to sustain growth. This is one of the main reasons for crop failure faced by farmers due to unexpected weather conditions.

 

“It is useful to be able to control the timing of cotyledon opening in order to prevent undue losses and plant death. While it is known that a plant hormone called brassinosteroid (BR) inhibits the opening of the cotyledons in darkness and that light promotes cotyledon opening, the molecular regulation of the interplay between light and BR has hitherto not been well understood,” said Sourav Datta, Associate Professor, Department of Biological Sciences, IISER Bhopal. The IISER scientists have shown that a protein encoded by a gene called BBX32 negatively regulates light signalling and promotes BR signalling to inhibit cotyledon opening in the model plant Arabidopsis related to the mustard family.