Question

Phytoalexins produced by plants in response to fungal infections are
A. Phenolic compounds
B. Glycoproteins
C. Proteins.
D. Lipids

Answer 1

Hint:This compound is the most common antioxidant in vegetables and fruits. It also protects some particular tissues from oxidative stress.

Complete answer:
Phytoalexins produced in plants function as toxins to the attacking organism. They can puncture the cell wall, delay maturation, interrupt metabolism, or prevent the replication of the pathogen concerned. Their significance in plant safety is demonstrated by an improvement in the sensitivity of plant tissue to infection when phytoalexin biosynthesis is inhibited. Mutants unable to produce phytoalexin show more severe pathogen colonisation relative to wild animals. As a result, host-specific pathogens capable of reducing phytoalexins are more virulent than those unable to do so.

Phenolic compounds are secondary metabolites that are formed in plant shikimic acid and pentose phosphate by means of phenylpropanoid metabolism. They include benzene rings with one or more hydroxyl substitutes which vary from clear phenolic molecules to strongly polymerized compounds. Phenolic and polyphenolic compounds are decreasing agents that safeguard the body's particular tissues from oxidative stress in isolation with vitamins like vitamin E, carotenoids, and vitamin C. However, polyphenols are the most prevalent antioxidants in fruit and vegetable diets. Phytoalexins are a phenolic compound developed in the host cell for protection against fungal infection. These chemicals inhibit parasite development.

Thus, the correct answer is option A. i.e., Phenolic compounds.

Note:Phytoalexins are antimicrobial and often antioxidant compounds synthesised by plants that accumulate rapidly in areas of pathogen infection. They are broad spectrum inhibitors and chemically variable with different forms characteristic of specific plant species.