Table III.

Effect of NAA on lateral root (LR) initiation in wild-type primary roots

Media3-aNAA3-bTransferred RegionNew Growth
LR no.3-cLength3-dLRLR no.3-cLength3-dLR
cm cm
4.5/602.6 ± 1.501.1 ± 0.202.415.2 ± 5.204.7 ± 0.373.2
4.5/60 + 11.1 ± 1.801.2 ± 0.158.9565.1 ± 6.203.5 ± 0.2918.6
Fold increase over control3.85.8
4.5/0.024.7 ± 0.781.48 ± 0.253.17.9 ± 3.904.1 ± 0.411.9
4.5/0.02 + 7.5 ± 2.101.40 ± 0.155.3622.5 ± 6.002.7 ± 0.228.3
Fold increase over control1.74.4
  • F3-a  Seedlings were grown for 5 d on the indicated media. They were then transferred to the same media with or without NAA. Seven days later, the region of the root that was transferred and the region of new growth were separately cleared and analyzed.

  • F3-b  NAA, prepared in 0.1n NaOH, was added to a final concentration of 100 nm. In control plates, an equivalent volume of 0.1n NaOH was added.

  • F3-c  All lateral roots and microscopic root primordia were counted. Lateral root nos. after NAA treatment were sometimes difficult to assess accurately because many of the primordia become confluent. Means ±sd are given for 10 roots.

  • F3-d  At the time of transfer, the root tip position was marked on the plate. The length of the transferred region was measured from hypocotyl/root junction to the mark. The new growth was measured from the mark to the root tip. Means ± sd are given for 12 to 20 roots.