The Impact of Urbanization on the Distribution of Spontaneous Herbaceous Plants in an Ancient City: A Pilot Case Study in Jingzhou, China.

Spontaneous herbaceous plants (SHPs) play an essential role in urban biodiversity. Research on the diversity of SHPs has profound implications for the conservation of urban biodiversity and green space management in the process of urbanization. We investigated the habitat, life form, and growth form of SHPs by combining samples and inspections in Jingzhou, in central southern China. Additionally, we chose three typical regions-Ji'nan, Gucheng, and Shashi-for the examination and comparison of biodiversity. The results showed that diverse habitats provided abundant living space for SHPs of different growth forms and life forms in Jingzhou. Water edges with higher humidity do not significantly support more SHP growth forms and life forms, except for pseudo-rosette, partial-rosette, and perennial plants. In addition, both wasteland and road gaps and slopes support significantly more SHP growth forms, including erect, tussock, and others. Wasteland supported the vast majority of species, both growth forms and life forms. In the diverse habitats, there are 352 plant species belonging to 70 families and 236 genera in Jingzhou (Ji'nan 184 species, Gucheng 157 species, and Shashi 127 species). Plant species diversity differed according to the level of management. The Ji'nan region had a large number of SHP species because of the less disruptive and milder management implemented in this region. SHPs show good performance and can provide wild landscape effects; therefore, they have the potential to be used in many urban landscaping applications. In the process of urbanization expansion, we should implement the concept of protection and coordinated development in new construction areas. Our study has important implications for the support of SHPs in urban areas.

The appropriate expression and coordination of glycolate oxidase and catalase are vital to the successful construction of the photorespiratory metabolic pathway.

Photorespiration has emerged as a hotspot in the evolution of photosynthesis owing to the energy loss during the process. To ensure the physiological functions of photorespiration such as light protection, H2O2 signaling, and stress resistance, separate the photorespiration glycolic acid flow, and minimize photorespiration loss, a balance must be maintained during the construction of photorespiratory metabolic branch. In this study, glycolate oxidase (GLO) and catalase (CAT) were introduced into potato (Solanum tuberosum) chloroplasts through the expression of fusion protein. Through the examination of phenotypic characteristics, photosynthesis, anatomical structure, and enzyme activity, the efficiency of the photorespiration pathway was demonstrated. The results showed that certain transgenic lines plants had shorter plant height and deformed leaves and tubers in addition to the favorable photosynthetic phenotypes of thicker leaves and larger and denser mesophyll cells. By Diaminobenzidine (DAB) staining analysis of the leaves, the intermediate H2O2 could not be decomposed in time to cause biomass decline and malformation, and the excessive glycolate shunt formed by the overexpression of the fusion protein affected other important physiological activities. Hence, the appropriate and coordinated expression of glycolate oxidase and catalase is essential for the establishment of photorespiration pathways in chloroplasts.