​Pollen tube growth in the transmission tract (TT) of the style and its attraction to the embryo sac are directed by chemical cues in plants, as discovered in Lily and Torenia. Which one of the following statements about the proteins/peptides secreted in the process is correct?​

Correct option is B

Sol.

• The transmission tract (TT) epidermis secretes cysteine-rich adhesins, which help pollen tubes adhere and grow through the style.

• The synergid cells (SY) secrete cysteine-rich defensin-like peptides, which play a role in signaling and guiding the pollen tube towards the embryo sac.

• This interaction ensures proper pollen tube guidance and successful fertilization.

• Other options either reverse these roles or misassign peptide secretion.

Information Booster:

• Cysteine-rich adhesins in the TT provide adhesive support for pollen tube growth.

• Defensin-like peptides secreted by synergids act as chemoattractants and signaling molecules to direct pollen tube growth to the micropyle.

• Proper secretion and signaling are crucial for reproductive success in flowering plants.

  
  
• Additional Information on Incorrect Options:

• Option 1 reverses adhesin and defensin-like peptide secretion.

• Option 3 incorrectly states TT secretes glycoproteins and synergids secrete adhesins and chemocyanin.

• Option 4 incorrectly assigns LURE peptides to the central cell rather than synergids.