Antioxidant Response, Phenolic Compounds and Yield of Solanum tuberosum Tubers Inoculated with Arbuscular Mycorrhizal Fungi and Growing under Water Stress

Abstract

Solanum tuberosum (potato) is one of the most common crops worldwide; however, it is sensitive to water stress, which necessitates the identification of alternative tools to improve their production. Here, we evaluated the inoculation of two arbuscular mycorrhizal fungi (AMF) strains, Claroideoglomus claroideum (CC), Claroideoglomus lamellosum (HMC26), and the MIX (CC + HMC26) in yield and phenolic and antioxidant response using chromatographic and spectroscopic methods in potato crops, at increasing levels of water stress, namely, with 100% (0), 70% (S1), and 40% (S2) soil humidity. Two caffeoylquinic acid isomers were detected and their levels showed a tendency to increase under stress together with the AMF inoculation, reaching up to 19.2 mg kg−1 of 5-caffeoylquinic acid and 7.4 mg kg−1 of caffeoylquinic acid isomer when CC was inoculated, and potato plants grew at the highest water starvation condition (S2). Regarding antioxidant activities, a differentiated response was detected depending on the AMF strain, highlighting the effect of HMC26 on Trolox equivalent antioxidant capacity (TEAC) method and CC in cupric reducing antioxidant capacity (CUPRAC) method, reaching up to 1.5 μmol g−1 of TEAC in plants inoculated with HMC26 and 0.9 μmol g−1 of CUPRAC in plants inoculated with CC, both in potato tubers of plants growing under the S2 stress condition. Meanwhile, the use of AMF did not influence the number and biomass of the tubers, but significant changes in the biochemical properties of tubers were observed. The results suggest that specific AMF adaptations to water stress must be considered when inoculation procedures are planned to improve the yield and quality of tubers in potato crops.

Physiological and Enzymatic Antioxidant Responses of Solanum tuberosum Leaves to Arbuscular Mycorrhizal Fungal Inoculation under Water Stress

“…However, the increase varied depending on the potato variety (Arinda, Agria and Santé) [ 21 ]. In potato tubers where two AMF strains ( C. claroideum and C. lamellosum ) were used, there were improvements in non-enzymatic antioxidant activity, being higher with the C. lamellosum strain [ 50 ].…”