Molecular Plant Breeding, 2016, Vol.7, No.16, 1-7
3
Figure 1 A schematic diagram of Ethylene Biosynthetic pathway (Idea taken from Kevin L.C. Wang, Hai Li, and Joseph R. Ecker.
2002. Ethylene Biosynthesis and Signaling Networks. The Plant Cell, S131–S151, Supplement 2002,
© 2002
American Society of Plant Biologists).
Similarly, two ethylene regulated genes, E4 and ER69
have been identified (Zegzouti et al., 1999) and these
both genes are involved also in methionine cycle,
encoding methionine sulphoxide reductase protein and
cobalamine-independent
methionine synthase
respectively (Montgomery et al., 1993 and Zegzouti et
al., 1999). In addition to E4, another gene E8 is also
ethylene dependent for its induction (Lincoln et al.,
1987). Although expression of E4 gene is induced in
leaves in response to ethylene while it is not in case of
E8 gene, predicting that their ethylene regulation is
tissue specific and even developmentally regulated
(Lincoln and Fischer, 1988).
4 Effect of Ethylene on Plant Physiolog
y
Ethylene has crucial impact on the growth and
development of plant. This simple, gaseous plant
hormone affects and regulates the cell division, cell
size and cell differentiation; thereby it has major effect
on plant physiology. Plant growth and developmental
changes are synchronized and under hormonal control.
Therefore any mutation in ethylene synthesis related
genes as well as ethylene signaling related genes
would affect and alter the timing of plant
developmental processes, thus this type of mutation is
heterchronic mutation (Tsuchisaka and Theologis,
2004).
Ethylene modulates and alters developmental
processes and growth dynamics such as seed
germination, growth and development of plants organs,
ripening and maturing as well as organs senescence
and abscission (Schaller and Kieber, 2002). Ethylene
induces and control root induction and formation, root
nodules formation in leguminous crops, restricts the
development of bulbs and tubers, stimulates the
