Sex-specific physiological and biochemical responses of Litsea cubeba under waterlogging stress

The sex of dimorphic plants is affected by stress tolerance. Litsea cubeba is a diecious species of ecological importance in southern China, and waterlogging is one of the most common abiotic stressors that this species suffers. However, differences between male and female L. cubeba under waterlogging stress have not been well studied. In this study, we examined the sex-specific physiological, metabolic, and biochemical responses of L. cubeba to waterlogging. The results showed that female and male L. cubeba plants exhibited sex-related dif-ferences in response to waterlogging stress. Males under waterlogging conditions experienced more serious oxidative damage than females, whereas females of L. cubeba under waterlogging conditions possessed superior antioxidant defense systems, including better enzymatic and nonenzymatic antioxidants, higher total chlorophyll and carotenoid contents, higher fermentative enzyme activities and root activity, and higher soluble sugar and proline contents. In addition, females exhibited higher malondialdehyde, ascorbic acid, and glutathione contents in the Yifeng (YF) and Huangshan (HS) varieties, whereas males had higher malondialdehyde, ascorbic acid, and glutathione contents in the Baise (BS) and Jiangle (JL) varieties. These results indicate that although the level of membrane lipid peroxidation and degree of damage to the membrane structure were higher and more serious in females under waterlogged stress, females possessed better cellular defense mechanisms against damage and could maintain a better cellular balance between defense and damage. Comprehensive indicators showed that female plants of L. cubeba are more tolerant to waterlogging than males, which would contribute to developing a sustainable population and maintaining a stable yield. Overall, our research provides insights into the adaptation mechanisms of L. cubeba trees subjected to waterlogging stress and provides a better understanding of sexually dimorphic responses to waterlogging stress.