Figure 2.

The effects of different hormones and CKs on 7-d-old Col seedling roots to determine their roles in CK-induced root growth. Seeds were sown on 3% G and various hormone-containing half-strength MS medium and grown vertically in the light. The significant extent of the CK-induced root growth response was found only with BAP, while ACC could also bring about very little response but at a very high concentration. The CK-induced root growth response was not visible in 3% G and different concentrations of IAA-, epibrassinolide (EBR)-, GA₃-, or ABA-containing half-strength MS medium. Among the various CKs tested, all naturally occurring CKs (trans-zeatin [t-Z] and 2-isopentenyladenine [2-iP]) could evoke CK-induced root growth to a similar extent as with BAP, in contrast to synthetic CK kinetin (inset). The data presented are averages of three biological replicates, with each replicate having 30 seedlings and error bars representing sd. Student’s t test, P < 0.05, n = 3 biological replicates.