BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Cytokinin is generally considered to promote mitotic cell division in the shoot, but differentiation and transition to the endocycle in the root. Here we consider recent data on the inputs by which cytokinins positively and negatively regulate transitions through the cell cycle.

Detailed explanation-2: -Cytokinins promote cell division and increase cell expansion during the proliferation and expansion stages of leaf cell development, respectively. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period.

Detailed explanation-3: -Auxin promotes cell division and meristem maintenance and also plays an important role in the establishment of cellular patterning.

Detailed explanation-4: -The hormone cytokinin promotes cell differentiation in plant roots by repressing both auxin transport and responses to auxin at the boundary between the meristem and the root elongation zone.

Detailed explanation-5: -During phototropism and gravitropism, the plant hormone auxin controls cell elongation. The plant hormone cytokinin promotes cell division, controling many developmental processes in plants.