Overcoming self-incompatibility in Ipomoea cairica by IAA

A possible regulatory role for ethylene in the pollen-pistil interaction in a sporophytic self-incompatible system

“…The role of IAA in sporophytic self-incompatibility has been described previously [18] . By studying the effects of a known precursor of ethylene and an inhibitor of its action, the present work was designed to test whether IAA-induced ethylene is involved in this phenomenon .…”

“…Its effect was studied both on cross-compatibility and self-incompatibility behaviours of I. cairica . AgNO3 inhibition of crosscompatible pollen tubes is likely to be due to its effect on ethylene, which is induced by the presence of sufficient endogenous levels of IAA in such a mating [18] . Thus, these observations support a probable regulatory role of ethylene in compatible tube growth .…”

“…The latter is important because genetic homogeneity ensures the most favourable comparison of treatments . In general, the methods of maintaining, selecting, treatment of test parts as well as scoring the results for the present study were the same as described earlier [14,18] . For treating pollen or pistil tissue, 0.5 ml of ethanol or water, containing the required concentration of the compound to be tested was introduced into a small vial .…”

“…In further experiments, AgNO 3 was used in combination with indole-3-acetic acid (IAA) which is known to promote self-pollen germination and further tube growth [18] .…”

“…However, studies involving exogenous application of various growth regulators either individually or in combinations have been made . The first investigation involved exogenous application of IAA [18] . Later, studies were extended to ethylene, since IAA, which promoted self-pollen germination and further tube growth [18], has been shown to induce ethylene production in some plant systems [7,10,12] .…”