Chitosan Increases the Sensitivity of Soybean Under Iron Deficiency by Impairing the Antioxidant Mechanisms and Nutrient Balance


AKSOY E.

Journal of Plant Growth Regulation, 2024 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2024
  • Doi Number: 10.1007/s00344-024-11520-7
  • Journal Name: Journal of Plant Growth Regulation
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Agricultural & Environmental Science Database, BIOSIS, CAB Abstracts, Chemical Abstracts Core, Food Science & Technology Abstracts, Veterinary Science Database
  • Keywords: Antioxidant enzymes, Chitosan, Gene expression level, Genotypic variation, Iron deficiency, Tolerance
  • Middle East Technical University Affiliated: Yes

Abstract

Iron (Fe) deficiency is a common problem, especially in alkaline soils, and large yield losses are experienced in sensitive plants such as soybean (Glycine max L.) when they are grown on alkaline soils. Natural and organic products can be used as fertilizer alternatives to complex with a small amount of Fe in the soil and make it available for the plant roots for effective uptake. For this reason, the effectiveness of chitosan application in different doses was studied in two soybean cultivars (tolerant—Arısoy and sensitive—Atakişi) under Fe deficiency. Plants were grown in hydroponic media containing 60-µM (Fe-sufficient) or 6-µM (Fe-deficient) Fe-EDTA supplemented with chitosan in different concentrations (0.5, 1, 1.5, and 2%) until the V2 stage. An increase in Fe deficiency symptoms was observed in plants due to the increased chitosan concentration. Iron deficiency-related genes were induced after chitosan application. Fe, Mn, Zn, and Mg concentrations were altered significantly in the sensitive cultivar after chitosan application. Therefore, chitosan application cannot rescue Fe deficiency; on the contrary, it impacts the availability of other divalent metals to plants. These alterations resulted in increased H2O2 and MDA, and decreased proline levels. All these changes were more drastic in IDC-sensitive soybean cultivar. Antioxidant enzyme activities varied between cultivars, with Arısoy relying on catalase and superoxide dismutase, while Atakişi favored ascorbate peroxidase. Overall, chitosan application from the roots leads to oxidative stress due to the altered nutrient balance under Fe deficiency.