The effect of foliar application of the amino acid tryptophan and drought stress on the altered relative expression patterns of certain genes in the indole-alkaloid TIAs pathway, as well as enzymatic and non-enzymatic antioxidants in the leaves of th

Document Type : Research Paper

Authors
1 Faculty of Agriculture, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran.
2 Department of Production Engineering and Genetic Modification, Faculty of Agriculture, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran.
3 Department of water engineering, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran.
4 6- Department of Production Engineering and Plant Genetics, Faculty of Agriculture and Natural Resources, Lorestan University, Khorramabad, Lorestan, Iran.
10.22034/jpr.2025.8573.3391
Abstract
Periwinkle is a highly valuable medicinal herb as it is the only source for the production of the anticancer drugs vinblastine and vincristine. The low synthesis and high cost of the drugs derived from the Periwinkle, along with water scarcity as one of the biggest limiting factors in agriculture, led to this research focusing on the effects of the amino acid tryptophan and drought stress on the changes in secondary metabolites of Periwinkle and the genes associated with the synthesis pathways of vinblastine and vincristine. This study was conducted in a completely randomized design with three factors: tryptophan spraying (0 and 250 ppm), drought stress (40 and 100% field capacity), and time (24, 48, 72, and 168 hours) for evaluating relative expression. The assessment of changes in expression pattern showed the highest relative expression for the Dat and Prx genes in all three conditions at 24 hours and 168 hours compared to the control. The Tdc gene, the 24 and 72-hour treatments after applying tryptophan and the 168-hour tryptophan-drought treatment showed down-regulated in relative expression, while other treatment levels showed an increase in relative expression compared to the control. From a physiological perspective, the highest dry weight of the plant was obtained in the tryptophan spraying treatment. Additionally, drought stress and tryptophan led to an increase in the activity of catalase and peroxidase, as well as the content of phenols and flavonoids, with the highest levels of each observed at concentration of 250 ppm under 40% drought stress of FC.

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Articles in Press, Accepted Manuscript
Available Online from 19 April 2025

  • Receive Date 24 December 2024
  • Revise Date 13 March 2025
  • Accept Date 09 April 2025

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