Senescence

 

 

Senescence is a sequence of biochemical and physiological events that comprise the final stage of development. During senescence, leaf cells undergo dramatic changes in cellular metabolism and the sequential degeneration of cellular structure in an orderly manner.
Leaf senescence, although deteriorative in nature, is an evolutionarily acquired genetic process, which is a crucial for the fitness of plants as an altruistic trait. So, It is likely that many genes regulate senescence. Thus, genetic analysis of the process is necessary to understand the process better.

In monocarpic plants such as Arabidopsis and rice, controlling life span of a leaf in association with reproduction is an evolutionarily acquired strategy to maximize fitness of a plant by remobilizing nutrients accumulated during growth phase to developing seeds
In autumn leaves, nutrients are remobilized to stems or younger organs
in concomitance with removal of dysfunctional organs.

 

 

To better understand the senescence process

 

The underlying regulatory mechanisms are barely known, despite the long-standing interest in senescence process. So, the identification of genes that alter senescence has practical value and is helpful in revealing pathways that influence senescence

 

 

 

 

- Examination of the role of ECI1 protein in regulating leaf senescence
- Construction of transcriptional network among ARRs & Elucidation of their functions
- Construction of senescence regulatory pathway

 

 

 

 

- Physiological approaches : Photochemical efficiency , Chlorophyll content, and membrane ion leakage
- Molecular approaches : Expression of SAGs and photosynthesis related genes Microarray and Proteomics
- Genetic approaches : Screening of suppressors and double mutant analysis

 

 

Molecular mechanism of senescence
- A critical developmental process

Important practical applications
- Plant productivity
- Post-harvest storage characters
- Delay of organ senescence (floral organs, fruits)