Question

Pneumatophores are found in
(a) Mesophytes
(b) Sciophytes
(c) Halophytes
(d) Heliophtyes

Answer 1

They are plants which will survive and complete their life cycle in salt concentrations of 200 mM NaCl. Pneumatophores have roots which are the horizontal roots growing vertically upwards and forming loops downwards to resemble a bent knee.

Complete step by step answer:
- Pneumatophores: Erect roots that are extensions of the underground rootage. These roots have exposed a minimum of a part of the day and not submerged underwater, the basic system can obtain oxygen in an otherwise anaerobic substrate.
- Halophytes are often further categorized as euglenophytes (true halophytes) , pseudo halophytes (salt avoiders) and crinoid halophytes (salt excretion) .
- Avoidance is the process of keeping the salt ions away from the parts of the plant where they are harmful are:
Salt Exclusion
Salt Extrusion
Salt Dilution Tolerance
Osmotic adjustment
- Hormone synthesis - Abscisic acid which is a stress hormone plays an important role in hardens plants against excess salts, detoxification, and growth control.
- Importance:
River mangrove—the source of best honey.
Medicines- Treatment of skin disorders and sores including leprosy. Headaches, rheumatism, snakebites, boils, ulcers, diarrhoea, and lots of more conditions are traditionally treated with mangrove plants.
Hardwood- used for boat building and cabinet timber.
- One of the striking features of most of those halophytes is the correlation between uptake of cations and whole plant succulence.
- Those of Sonneratia species are bark- covered and should reach heights of three metres.
- Pneumatophores project through the sediment surface from underlying cable roots and performance primarily in gas exchange.
So, the correct answer is ‘(c) Halophytes.’

Note:
- Salt adaptation in halophytes
Depend on adaptation to low osmotic potential and high salt concentrations within the external solution.
Effector molecules that cause salt adaptation, and regulatory molecules, which regulate amounts and activities of effectors.
- Physiology of Halophytes
Several key enzyme systems and genetic control mechanisms are identified.
Halophytes use the controlled uptake of Na+ into cell vacuoles to drive water into the plant against a coffee external water potential (through SOS) .