Question

Provide experimental evidence for auxin’s involvement in:

a. embryo patterning

b. root formation

c. cotyledon/leaf formation

d. vein formation

e. cell elongation

f. photo- and gravi-tropism

g. apical dominance

Answer 1

a.Maternal auxin supply contributes to early embryo patterning in Arabidopsis.

• Most pattern formation steps in the early Arabidopsis embryo depend on auxin biosynthesis, transport, and response.

​​​​b.The effect of auxin of shoot origin on the growth and development of the root system of Pisum sativum L. cv. Kelvedon Wonder was investigated.

• Root growth was reduced when auxin transport from shoot to root was interrupted, but this could have been caused by a reduction in assimilate supply rather than a deficiency of auxin.

c.Coordination of auxin-triggered leaf initiation by tomato LEAFLESS.

• Plant leaves form at the flanks of the shoot apical meristem in response to cues provided by the phytohormone auxin. Auxin signals determine the sites of leaf initiation and bulging, a process followed by gradual and ongoing differentiation of leaf tissues.

d.Requirementf Auxin for Leaf Vein Pattern in Arabidopsis.

• Auxin Inhibitors Affect Leaf Vein Pattern.

e. Effects of auxin on cell elongation of Maize coleoptile.

f. Effects of Auxin on Arabidopsis thaliana for Phtotropism and gravitropism.

When a plant senses a directional light stimulus it redistributesits auxin molecules to the side that is further away from the light. As a consequence, the plant cells that are further away from the light experience a greater concentration of auxin and grow faster, causing the shoot to bend towards the light.