How does senescence benefit a plant?
The main function of leaf senescence is nutrient recycle and, since this confers an adaptive advantage, it can be considered an evolutionary selected process. Multiple developmental and environmental signals control senescence, and among them plant hormones are understood to play important roles.
What is the importance of senescence?
Senescence is the final stage of plant development during which the plant reclaims the valuable cellular building blocks that have been deposited in the leaves and other parts of the plant during growth. Maintaining an efficient senescence process is essential for survival of the plant or its future generations.
What is senescence in agriculture?
Senescence is a developmental process which in annual crop plants overlaps with the reproductive phase. Senescence might reduce crop yield when it is induced prematurely under adverse environmental conditions. This review covers the role of senescence for the productivity of crop plants.
How many types of senescence are there in plants?
At the cellular level, senescence can be classified into two categories: mitotic senescence and postmitotic senescence as discussed below.
How do cytokinins prevent senescence?
Cytokinin production slows down the process of senescence. However, accumulation of sugars during senescence, due to the breakdown of accumulated starch or the preferential export of N2 from the leaf, can block the effect of cytokinin, especially in low light.
What happens during senescence in plants?
Plant senescence is the process of aging in plants. Plants have both stress-induced and age-related developmental aging. Chlorophyll degradation during leaf senescence reveals the carotenoids, such as anthocyanin and xanthophylls and is the cause of autumn leaf color in deciduous trees.
What are the types of senescence?
Types of Senescence
- Whole plant senescence.
- Shoot Senescence.
- Sequential senescence of Organ senescence.
- Simultaneous senescence.
What is the process of abscission?
Abscission is a process that initiates the removal of a part of plant following the formation of a protective layer or scar tissue that prevents the entry of pathogen and protects the inner tissues from desiccation. Plants are shedding organisms. Trees shed inactive xylem internally as heartwood.
What hormone prevents senescence leaves?
Cytokinins help to maintain the plant cell and expression of cytokinin biosynthesis genes late in development prevents leaf senescence.
Is auxin responsible for senescence?
One study supports the positive role that auxin plays in senescence, reporting that the GmSARK gene, isolated from soybean and expressed in Arabidopsis, promotes leaf senescing (Xu et al., 2011). In contrast, other studies have reported a negative role of auxin in leaf senescence.
Does cytokinin promote senescence?
Cytokinins modulate a number of important developmental processes, including the last phase of leaf development, known as senescence, which is associated with chlorophyll breakdown, photosynthetic apparatus disintegration and oxidative damage.