a meristem is a region of actively dividing cells. the apical meristem is applicable to both stems and roots. the lateral meristem is responsible for the thickening of the stem for support.

auxin is responsible for cell elongation. so when plants are illuminated from above auxin is evenly distributed among the stem making the plant grow straight towards the light. when a plant is receives light from a side the auxin is re-routed to the shaded cells thus causing more rapid growth than the side receiving the light. this is what causes the plant to grow towards the light. this is called phototropism or the curvature of a plant organ in response to light.

so when you top a plant, you are getting rid of the apical meristem and the auxin is then re-routed to the auxillary bud primordium that are laying dormant until they receive the auxin and they start to grow due to a new apical meristem. thus giving you two main colas instead of one.

jd, inihibits means to hinder, restrain or stop from growing.

sorry if this is a little confusing but we are getting down to the cellular level.


-shake