Abstract
This study focused on the chemical synthesis of auxin analogs, wherein a trifluoromethyl group was introduced near the carboxyl group in the side chain of natural and synthetic auxins, including IAA, NAA, IBA, 2,4-D, and 4-Cl-IAA. The effects of these synthetic compounds and natural auxins on plant growth regulation and callus growth were evaluated. In experiments with black gram, CF(3)-IAA and 4-Cl-CF(3)-IAA exhibited comparable effects to the parent compound, IAA. Meanwhile, CF(3)-NAA, CF(3)-2,4-D, CF(3)-IBA-1, and CF(3)-IBA-2 displayed effects that differed considerably from those of their respective parent auxins. In experiments with lettuce, CF(3)-IAA, 4-Cl-CF(3)-IAA, CF(3)-NAA, CF(3)-2,4-D, and CF(3)-IBA-1 showed effects comparable to the corresponding parent auxins. However, at low concentrations, these analogs induced hypocotyl and root elongations, a response distinct from that observed with their parent compounds. Furthermore, CF(3)-IBA-2 considerably promoted hypocotyl and root elongations across all concentrations relative to the control. The addition of synthetic compounds to callus cultures revealed that CF(3)-IAA, 4-Cl-CF(3)-IAA, CF(3)-NAA, and CF(3)-2,4-D promoted callus proliferation, whereas CF(3)-IBA-1 and CF(3)-IBA-2 did not enhance callus growth.