Kinetin (50 and 100 mg 1−1) inhibited both the shoot and the root growth. Inhibition of root growth by kinetin is considered to be mainly due to inhibition of protein synthesis. Vitamins of the B groupviz., riboflavin, thiamin, niacin and pantothenic acid are found to be antagonistic to kinetin in reversing the inhibition of protein synthesis of the root. Vitamins, probably by acting as inducers of protein synthesis, antagonized the action of kinetin. The response of kinetin to shoot protein content is different from that of the root.

The photosynthetically efficientC₄ plantsviz Amaranthus viridis, Euphorbia hirta and aC₃ plant,Acalypha indica with mosaic leaf pattern showed the maximum amount ofB vitamins when compared to the otherC₃ plants. It is observed that photosynthesis and vitamin synthesis go hand-in-hand showing close correlation. The results also indicate that there is a close relation between chlorophyll content and vitamin content. However, there appears to be no relation between phyllotaxy and photosynthesis. Between the twoC₃ plants,viz., Acalypha andCarica, the photosynthetic inefficiency of the latter might be due to more of chlorophyllb and less of chlorophylla as seen from chlorophylla/chlorophyllb ratios.