3.4 Effects of nano-Se application on flavone compounds and
phenolic acids in wheat seedlings.
Flavone compounds and phenolic acids play an important role in plants to
defense against pests and disease (Czerniewicz, Sytykiewicz, Durak,
Borowiak-Sobkowiak, & Chrzanowski, 2017). In general, the concentration
of flavone compounds and phenolic acids increased with nano-Se
treatment, especially at the application rate of 5.0 mg/L (Figure 4).
The flavone compounds measured in this study included quercetin,
luteolin, apigenin, rutin, kaempferol and myricetin which all increased
to varying degrees after application of nano-Se. Among these compounds,
luteolin demonstrated the greatest increase, increased by 1.7 times, 1.3
times, and 1.1 time after the application of nano-Se at 1.0, 5.0, and
20.0 mg/L. Nano-Se (5mg/L) increased apigenin, quercetin, and rutin
levels by 100.0, 14.5, and 22.2%, respectively. However, kaempferol and
myricetin levels were unchanged across nano-Se treatments.
As for the phenolic acids, compared to the controls, nano-Se (5.0mg/L)
applied could increase the caffeic acid, hydroxy-3, 5-dimethoxycinnamic
acid, 4-hydroxybenzoic acid, 4-hydroxycinnamic acid, and chlorogenic
acid levels by 74.9, 73.6, 98.0, 38.0, and 14.7%, respectively.
However, the ferulic acid, syringic acid, and vanillin acid contents
have non-obvious change. The results indicate that the application of
nano-Se at 5.0 mg/L could invoke the changes in the concentration of
plant secondary substances in wheat seedlings.
3.5 Effects of significant
difference of exogenous onS. avenae growth.
As shown in Figure 5 A, compared to control, aphid number reduced by
42.9 % (nano-Se5), 35% (MT10), and 52.2% (the combination of nano-Se5
and MT10), respectively. The nano-Se application increased the DIMBOA,
MT, and JA concentration by 31.1%, 57.0%, and 43.6% respectively. The
MT application enhanced DIMBOA, MT, and JA levels by 31.8%, 62.8%, and
38.2%, respectively. The combined application of nano-Se5 and MT10
enhanced the DIMBOA, MT, and JA concentration by 34.8%, 70.8%, and
51.3%, respectively. The SA contents decreased by 42.2%, 37.3%, and
57.5% when treated with nano-Se, MT, and their combination (Figure 5B).
The expressions of DIMBOA (TaBx1A , TaBx3A , TaBx4A )
and MT (TaASMT2, TaCOMT ) related genes were determined (Figure
5C). Compared to the control, TaBx1A (254.7%), TaBx3A(40.0%), TaBx4A (55.9%), TaASMT2 (34.1%), andTaCOMT (12.3 times) were increased by nano-Se5. MT10 promote the
expression of TaBx1A (200.7%), TaBx3A (2.0%),TaBx4A (23.7%), TaASMT2 (8.4%), and TaCOMT(7.5 times). Their combination treatment increased the expression ofTaBx1A , TaBx3A , TaBx4A, TaASMT2 and TaCOMTby 405.2%, 52.5%, 103.4%, 52.3% and 25.3 times, respectively.