Unraveling Seasonal Allocation of Soluble Sugars, Starch and Proline in Sternbergia lutea

Abstract

This study focuses on Sternbergia lutea (L.) Ker Gawl. ex Spreng., a bulbous, perennial, autumnal flowering geophyte mainly distributed around the Mediterranean Basin. The seasonal content of total sugars, starch and proline in above- and below-ground plant parts in this study, which has hitherto not been the subject of a published study. Geophytes possess underground storage organs that support sprouting, leaf growth and flowering. Furthermore, their buds remain protected below the soil surface during periods of dormancy. Understanding the fluctuation of these compounds in S. lutea contributes to our knowledge of its adaptation to the Mediterranean ecosystem. It seems likely that monthly fluctuations in proline accumulation, sugar and starch content in both above- and below-ground tissues of S. lutea correspond to the distinct seasonality of the Mediterranean ecosystem. Elevated starch content was investigated in the bulbs, while lower starch content was estimated in the leaves. Substantial values of soluble sugar content have been detected in bulbs and leaves. Additionally, elevated sugar content was detected in the yellow petals of S. lutea in October. Pronounced proline accumulation was detected in the leaves and bulbs of S. lutea during its active and dormant phase, respectively.