Trade-offs in Root and Shoot Growth in Forage Pea [Pisum sativum (L.) arvense] with Foliar Applications of Synthetic Elicitor DPMP (2,4-Dichloro-6-{(E)-[(3-Methoxyphenyl) Imino] Methyl} Phenol) and SA (Salicylic Acid)

Abstract

Background: Climate change, abiotic and biotic stress pressure are forcing breeders and farmers to find alternative ways to improve and extend food production. Even though there are multiple ways to cope with stress conditions, alleviation of the stress by enhancing plant responses is one of the cheapest, environmentally safest and most direct ways. This study aimed to evaluate the effects of two common plant defense elicitors, 2,4-dichloro-6-{(E)-[(3-methoxyphenyl) imino] methyl} phenol (DPMP) and salicylic acid (SA) on plant growth and seedling vigor with forage pea [Pisum sativum (L.) arvense] as a model plant. Methods: Two different chemicals, 100 μM SA and 10 μM DPMP were evaluated in response to Polyethylene glycol 8000 (PEG) treatment in a semi-hydroponic growth system. Root architecture and shoot growth parameters were evaluated. The experiment was designed according to completely randomized design with three replications and ten plants per replication. Result: The effects of SA and DPMP foliar applications were significant on tap, lateral and total root lengths, number of lateral roots and root fresh weight. For most of the traits, SA and DPMP did not inhibit plant growth compared to control under treated and untreated conditions. Average lateral root length (aLatRL) was the noteworthy trait with significantly higher values in DPMP + unstressed conditions. Plants sprayed with DPMP had significantly higher (5.57 cm plant-1) aLatRL values compared to SA (4.53 cm plant-1) and control (3.01 cm plant-1). The results of the current study suggest that SA and DPMP foliar spraying can be beneficial to reduce the effects of abiotic stresses at optimal doses defined for each species. DPMP can be a candidate as a sustainable pesticide alternative and growth-enhancing agent, similar to SA.