Question

Explain what cue the floral cells are using to differentiate into the different parts (ie. sepal, petal, etc.)

Answer 1

Solution

• the gene AP2 is here responsible for the normal growth of sepals and petals in the first and second whorls of the organ primordial, respectively.
• According to ABC model of flower induction explains that gene A is responsible for sepal formation and gene A and B is for petal formation and gene B and C for stamen formation and C for carpel formation.
• exogenous (photoperiod, vernalization, stress, nutrients) and endogenous (florigen/antiflorigen concept, electrical signal concept and multifactorial control by PGR) factors that influence the flowering.
• At molecular level when plants receive proper endogenous and exogenous signals after attaining the competence, these floral repressors are down regulated, resulting in the flowering of plants.
• It is also authenticated by the presence of miRNAs—the RNAs of approximately 21-nucleotide length—whose function is to down regulate the mRNAs of their complementary sequence and they are never translated to protein.
• They are different from siRNAs. miRNA172 that targets AP2 gene for early flowering was also identified.
• The cell fate ind its expantion of cellulosic renforcement is responsible for formation of septal petal carpel and stamen primordial according to various signals explained above.