AUTHOR=Huang Ping , Shen Fangyuan , Abbas Adeel , Wang Hao , Du Yizhou , Du Daolin , Hussain Sadam , Javed Talha , Alamri Saud 

TITLE=Effects of Different Nitrogen Forms and Competitive Treatments on the Growth and Antioxidant System of Wedelia trilobata and Wedelia chinensis Under High Nitrogen Concentrations

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.851099

DOI=10.3389/fpls.2022.851099

ISSN=1664-462X

ABSTRACT=Nitrogen (N) is one of the essential nutrients for plant growth. Appropriate application of N can improve the N use efficiency (NUE) and significantly promote plants' growth. However, under N toxic conditions, the relationship between the growth and antioxidant system of invasive plants under different N forms and competitive treatments are not fully understood. Therefore, in this study, the performance of invasive species Wedelia trilobata and its native species Wedelia chinensis were evaluated under two sets of N forms and ratios: NH4+-N(AN)/NO3－-N(NN)=2:1 and NH4+-N(AN)/ NO3－-N(NN)=1:2 along with two intraspecific- and interspecific-competition under without N and high N level of 15 g N·m-2 year-1.  Data regarding the growth indices, antioxidant enzyme activities, including peroxidase (POD) and catalase (CAT), malondialdehyde (MDA), and proline contents were determined. Results showed that for competition treatments, growth status was better for interspecific competition than intraspecific competition. The plant biomass of W. trilobata was significantly higher than that of W. chinensis. Nitrogen significantly promoted the plants' growth in term of leaf area and biomass yield, and the antioxidant enzymatic activities were significantly increased under high N treatment than that of the control. Among N forms/ratios, AN/NN = 2:1 significantly enhanced the enzymatic activity, particularly in W. trilobata. Furthermore, for intraspecific competition, MDA contents of W. trilobata were decreased significantly compared to that of W. chinensis. In conclusion, our results showed that W. trilobata adapted well under competitive conditions through better growth and antioxidant defense system.