Question

Two students have compared the genome wide analyses of expression profiles in the leaves of maize and they found that the leaves of maize either do or do not develop kranz anatomy. Please explain.

Answer 1

Maize leaves has bundle sheath which surrounds veins and bundle sheath cells and again it surrounds mesophyll cells. Every pair of veins is thus seperated by two bundle sheath cells and two mesothelioma cells such an arrangement is called Kranz anatomy. These type of anatomy helps the plants in C4 photosynthesis. Researchers have determined genome wide analyses of expression profile in maize leaves and made the following conclusions. A GOLDEN 2 gene was identified in maize plant and later golden 2 (g2) mutant was identified. Zmglk 1 gene was determined in maize plant which has similar functions as g2. In C4 maize and C3 rice, presence of duplicate genes were determined which helps to propose that two Glk genes leads to development of single chloroplast in c3 type plants and one or two specialised chloroplast in c 4 type plants.