Page 268 - e-Book

In the IUT plants, nematode infection resulted in a decrease in the root/shoot ratio.

Due to reduced root growth and increased shoot growth, the root/shoot ratio has decreased.
Lower root growth owing to nematode infection was observed to cause water stress in plant

tops, resulting in a reduced root/shoot ratio (O'Bannon and Reynold, 1965).
Plant metabolism's role in pathogenesis has been thoroughly established by Giebel

(1982), Tayal and Agarwal (1982), and Sharma et al. (1996). It is now widely known that
numerous metabolites in the syncytial zone of galls play a role in the pathogenic mechanism's

combat mechanisms.

The invading pathogens' primary source of energy is stored carbohydrates, which are
transformed into usable form by hydrolytic enzymes released by the worm. As a result, the

sugar content of infected root and shoot tissues was depleted in the current study, and many

other researchers found comparable findings (Kannan and Balaji, 1988; Vaitheeswaran and
Mohamed Ibrahimand et al., 2008). The invading pathogens' primary source of energy is

stored carbohydrates, which are transformed into usable form by hydrolytic enzymes released
by the worm. As a result, the sugar content of infected root and shoot tissues was depleted in

the current study, and many other researchers found comparable findings.
It's also possible that the decrease in carbohydrate content is attributable to a decrease

in photosynthetic activity. Reduced photosynthetic pigments, as demonstrated in the current

study, support this viewpoint. One of the foregoing causes may be responsible for the fall in
sugar levels seen in the current investigations.

The rate of photosynthetic carbon fixation may potentially play a role in starch
production. The photosynthetic rate was also found to be reduced as a result of nematode

infection. Infected plants have lower chlorophyll levels. The drop in total starch content seen
in this study could be attributed to lower photosynthetic pigments caused by worm infection.

This is turning resulted in reduced starch synthesis in diseased plant. Infected untreated plants

showed an overall decrease in the activity of the -amylase, Alcohol dehydrogenase, and
Glucose dehydrogenase enzymes. The enzymes' lower activity is almost entirely attributable

to a lack of substrates. Lowered activities of dehydrogenase of alcohol and glucose in the root

and shoot were detected when the sugar in the infected plant was reduced, as this enzyme is
involved in carbohydrate metabolism (Kannan, 1984).

258