How does salinity affect the growth and photosynthesis in plants? Elucidate the avoidance mechanisms of salt stress by plants.
Salinity severely impacts plant growth and photosynthesis. High salt concentrations in soil create osmotic stress, making it difficult for roots to absorb water, leading to physiological drought. Excess ions like Na+ and Cl- become toxic, disrupting enzyme activity, damaging cell membranes, and causing nutrient imbalances. For photosynthesis, osmotic stress forces stomata to close, reducing CO2 uptake. Ion toxicity also directly damages photosynthetic machinery (chloroplasts), leading to reduced efficiency and oxidative stress.
Plants employ various avoidance mechanisms. Ion exclusion involves preventing excessive salt uptake by roots (e.g., in some mangroves). Some plants use specialized salt glands to excrete excess salt from their leaves (e.g., Atriplex species). Others utilize succulence, accumulating water in fleshy tissues to dilute internal salt concentrations. Leaf abscission is another strategy, shedding old, salt-laden leaves. These mechanisms collectively aim to prevent salt from accumulating to toxic levels in sensitive parts, thus maintaining growth.
Answered By:
Similar Questions
Briefly discuss significant features of heterosis and explain the dominance and overdominance hypotheses of heterosis, giving their main features.
Define Marker-Assisted Selection and give suitable examples. Discuss the applications of marker-assisted selection in recurrent selection, gene pyramiding and QTL introgression.
Define 'Grow-out test'. Explain briefly the methods of roguing in seed fields.
Define cell cycle. Describe different types and phases of cell cycle.
Classify plant mineral nutrients based on biochemical functions. How do excess minerals in the soil limit the plant growth?
Explain mutagenesis with its classification. Discuss briefly the mechanisms of action of alkylating agents and azide mutagens in crop improvement.
What do you mean by Intellectual Property? Discuss the protection of Intellectual Property Rights in reference to patent, plant breeders' rights and copyright.
Why do fruit plants need to be propagated vegetatively? Explain the advantages and disadvantages of asexual and sexual propagation.
Give an account on double haploid and its applications in plant breeding. Also discuss the production methods of haploid.
Explain the functions of plant cell wall in growth, development, maintenance and reproduction of plants.
Important Questions from Miscellaneous
Write a note in 150 words
Mendelian and non-Mendelian traits.Write a note in 150 words
Theoretical significance of Purum kinship-system.Write a note in 150 words
Smell as a signal among non-human primates.Write a note in 150 words
Osteodontokeratik culture and its makers.Discuss the Miocene hominoid remains and their significance in evolution.
