Exogenous phthalanilic acid induces resistance to drought stress in pepper seedlings (Capsicum annuum L.)

• DOI: 10.3389/fpls.2023.1156276
• Publication Date: 2023-09-28T05:30:58Z
• Authors: Xiaopeng Lu; Qiong Wu; Keyi Nie; Hua Wu; Guangyou Chen; Jun Wang; Zhiqing Ma
• Keywords: Capsicum annuum; Drought stress; Drought Resistance

Drought stress (DS) is one of the main abiotic negative factors for plants. Phthalanilic acid (PPA), as a plant growth regulator, can promote and development crops. In order to evaluate ideal application concentration frequency PPA-induced drought resistance in pepper ( Capsicum annuum ) seedlings, PPA was 133.3 mg·L −1 ; 200.0 266.7 , some key indicators were investigated, including leaf wilting index (LWI), relative water content (RWC), malondialdehyde (MDA). We found that LWI RWC PPA-applied leaves under light (LDS) moderate (MDS) all elevated, while MDA contents decreased. To better understand how makes resistant, we examined photosynthetic characteristics, parameters, antioxidant activities, osmotic substances seedlings treated twice with at LDS, MDS, severe (SDS). Results showed increased chlorophyll, height, stem diameter, root-shoot ratio, seedling SDS. The net rate (Pn), stomatal conductance (Gs), intercellular CO 2 (Ci), transpiration rates (Tr), water-use efficiency (WUE) PPA-treated LDS MDS improved, their limitation (Ls) reduced. also boosted activities enzymatic antioxidants (superoxide dismutase, catalase, peroxidase), well enhanced accumulation such soluble sugar, protein, free proline Thus, alleviate inhibition damage caused by DS, PPA-mediated efficacy may be associated improvement Pn, substances.