Defense Mechanisms of Chickpea against Chickpea Pod Borer, Helicoverpa armigera and Chickpea Leafminer, Liriomyza cicerina: from Plant Morphology to Molecular Level

Chickpea is cultivated
in more than 50 countries around the world,
with a growing market reaching more than USD 11 billion worldwide.
The annual production of chickpeas is around 1 t/ha, which is less
than the expected yield of 6 t/ha when grown under optimal conditions.
Insect pests are considered the major hindrance to chickpea production,
with chickpea leafminer (Liriomyza cicerina Rondani) and chickpea pod borer (Helicoverpa armigera Hübner) as the most spread and damaging ones. Host-plant
resistance is the most effective control strategy to significantly
reduce the use of pesticides and their side effects on beneficial
organisms and the environment. This perspective aimed to highlight
the mechanisms of defense of chickpea against its most damaging insect
pests H. armigera and L. cicerina. In chickpeas, antixenosis and antibiosis
are the most commonly reported resistance types. The key identified
traits associated with the antixenosis defense against insect pests
include trichomes on the leaf surface, organic acid exudation, and
leaf size. The antibiosis resistance of chickpeas is related to the
pod thickness, high content of phenolics, flavonoids, organic acids,
defense enzymes, proteinase inhibitors, and attractiveness capacity
of natural enemies. Docking results indicated that flavonoid compounds
were successfully docked into the chymotrypsin and carboxypeptidase
active sites, predicting the inhibitory capacity of these compounds
against the digestion of proteins in the pod borer. The overall mechanisms
of defense of chickpeas are governed by several quantitative trait
loci (QTLs) located in eight linkage groups (CaLG01–CaLG08).
In addition to biochemical compounds and proteinase inhibitors, the
mechanism of defense of transgenic chickpeas has also been discussed.