*Chemistry and Role of Flavonoids in Agriculture: A Recent Update DOI: http://dx.doi.org/10.5772/intechopen.106571*

and movement by using in nanomolar range. When flavonoids produce auxin gradients, they produce phenotypes with different morphoanatomical characteristics [68]. Stress-induced morphogenic responses of plants are controlled largely by flavonoids, which may have a direct relevance to flight strategies of sessile organisms exposed to unfavorable environments [69]. A species that produces dihydroxy flavonoids exhibits phenotypic characteristics that are strikingly different from a species that produces monohydroxy flavonoids [70]. In sunny situations, dwarf bushy phenotypes with few, tiny, and thick leaves are typically prevalent, shielding leaves deep in the canopy from light-induced severe cellular homeostasis disruptions. Alternatively, shaded plants, which contain kaempferol and/or apigenin derivatives, have long internodes and large leaf lamina, along with reduced leaf thickness [69]. PIN/MDR glycoproteins that facilitate cell-to-cell movement of auxin are inhibited by flavonoids at the plasma


#### **Table 3.**

*Example of some flavonoids and their rich dietary sources [74].*

membrane. In flavonoids, the catechol group is present at the B ring of the flavonoid skeleton that is responsible for inhibiting the activity of the efflux facilitator PIN and MDR proteins. The chemical structure of flavonoids also influences their action on IAA-oxidase significantly [71]. In recent years, it has been found that flavonoids can influence the activity of proteins involved in cell growth due to a nuclear location of flavonoids as well as the actions of enzymes that produce flavonoids [72]. This suggests that flavonoids may be able to regulate transcription [73]. In **Table 3** showed some flavonoids and their rich dietary sources [74].
