Non-Structural Carbohydrate Content and C:N:P Stoichiometry in Houpoea officinalis Flowers in Response to Development Stages

Mineral elements and non-structural carbohydrates (NSCs) are important nutrients and energy sources for flower development in plants. However, no studies were reported on the dynamic changes of nutrient stoichiometry and NSC contents in Houpoea officinalis (H. officinalis) flower. In this study, the changes in carbon (C), nitrogen (N), phosphorus (P), and NSC contents as well as C:N:P stoichiometry in the pistil, stamen, and petal of H. officinalis flowers at four developmental stages were comparatively analyzed. The results showed that C, N, P, and NSC contents, as well as C:N:P stoichiometric ratios in the three parts of the flower exhibited large variations at four development stages. Development stages and organs had significant effects on the measured parameters in the three organs of H. officinalis flowers, but their interactions had no significant effects. During the flower development, C, N, and P contents in different floral parts ranged from 418.7 to 496.3 mg/g, 26.6 to 45.3 mg/g, and 0.396 to 0.656 mg/g. P content decreased continuously with development, C:N in stamen were significantly higher than those in other flower parts at the same developmental stage. Glucose, starch, fructose, and sucrose contents showed significant differences in three parts of H. officinalis flowers at four development stages. These differences may reflect differences in elemental storage capacity and biomass allocation patterns of H. officinalis flowers. In general, our data will help to improve our understanding of the relationship between NSCs and C:N:P stoichiometry in response to development stages and organs in H. officinalis flowers.