Seasonal variation in Photosynthetic Pigments, Phytohormones, and phenols of Teucrium Polium L. Growing in Wadi Halazien, Egypt

Document Type : Original Article

Authors

1 Department of Agriculture Biochemistry, Faculty of Agric. Al-Azhar University, Cairo, Egypt.

2 Department of plant Ecology and Ranges, Desert Research Center, Cairo, Egypt

Abstract

Teucrium polium L. known popularly as felty germander, is a perennial plant that grows in the dry climate of the Mediterranean region.It's a seasonal dimorphic plant, and it appears quite different in the winter than it does in the summer. The plant's apparent seasonal transformation reflects its adaptability to the stressful climatic conditions prevailing in winter or summer. Thus, this study aimed to investigate the effect of seasonal changes on photosynthetic pigments, phytohormones, and phenols of Teucrium polium L. that grows in Egypt. Results showed that the content of chlorophyll  was significantly decreased in summer, while the content of carotenoids were significantly increased with stress. Production of some organic compounds was significantly affected by seasons and significantly increased under stress conditions in the summer.  In conclusion, the tolerance of Teucrium polium L. to stress conditions was closely associated with the production of organic compounds, such as carbohydrates, proline, and phenolic compounds. Total carbohydrates and proline were the main active components in the osmotic potential (Ѱs) in Teucrium polium L. In the dry season, Teucrium polium L. exhibited the accumulation of Abscisic acid (ABA), which may alleviate the inhibitory effect of salinity on photosynthesis. Higher values ​​of phenols, carotenoids, and proline under stress conditions may improve tolerance of Teucrium polium L. to oxidative stress and help in scavenging the free radicals under stress conditions. Further studies are recommended to investigate the possibility of increasing the resistance of economic crops to drought and/or salinity stress by increasing the synthesis of osmotically active solutes through genetic engineering techniques.

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