Agrotechnology

Effects of low light on photosynthetic properties, antioxidant enzyme activity and anthocyanin accumulation in purple Pakchoi

13^th International Conference on Agriculture & Horticulture

September 10-12, 2018 | Zurich, Switzerland

Hongfang Zhu, Yuying Zhu, Cha Dingshi, Gu Weihong, Zhang Yongping and Chen Youyuan

Shanghai Academy of Agricultural Sciences, China

Posters & Accepted Abstracts: Agrotechnology

Abstract:

Anthocyanins are secondary metabolites that contribute to red, blue, and purple colors in plants and are affected by light, but the effects of low light on the physiological responses of purple Pakchoi plant leaves are still unclear. In this study, purple Pakchoi seedlings were exposed to low light by shading with white gauze and black shading in a phytotron. The responses in terms of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, anthocyanin biosynthetic enzyme activity, and the relative chlorophyll and anthocyanin content of leaves were measured. The results showed that chlorophyll b, intracellular CO2 content, stomatal conductance and antioxidant activities of guaiacol peroxidase, catalase and superoxide dismutase transiently increased in the shade treatments at 5 d. The malondialdehyde content also increased under low light stress, which damages plant cells. With the extension of shading time (at 15 d), the relative chlorophyll a, anthocyanin and soluble protein contents, net photosynthetic rate, transpiration rate, stomata conductance, antioxidant enzyme activities, and activities of four anthocyanin biosynthetic enzymes decreased significantly. Thus, at the early stage of low light treatment, the chlorophyll b content increased to improve photosynthesis. When the low light treatment was extended, antioxidant enzyme activity and the activity of anthocyanin biosynthesis enzymes were inhibited, causing the purple Pakchoi seedlings to fade from purple to green. This study provides valuable information for further deciphering genetic mechanisms and improving agronomic traits in purple Pakchoi under optimal light requirements. Recent Publications: 1. Pompelli M F et al. (2010) Photosynthesis and photoprotection in coffee leaves is affected by nitrogen and light availabilities in winter conditions. J. Plant Physiol. 167(13):1052-1060. 2. Zhang X L et al. (2011) Exogenous hydrogen peroxide influences antioxidant enzyme activity and lipid peroxidation in cucumber leaves at low light. Scientia Horticulturae. 129:656-662. 3. Wang L et al. (2012) Effects of shading on starch pasting characteristics of indica hybrid rice (Oryza sativa L.). PLoS One. 8(7):e68220. 4. Guo N et al. (2014) Anthocyanin biosynthetic genes in Brassica rapa. BMC Genomics. 15:426. 5. Miki S, Wada K C and Takeno K (2015) A possible role of an anthocyanin filter in low-intensity light stress-induced flowering in Perilla frutescens var. crispa. Journal of Plant Physiology. 175:157-162.

Biography :

Hongfang Zhu has working on Shanghai Academy of Agricultural Sciences since 2009. She has mainly engaged in the collection, arrangement and evaluation of pakchoi and Chinese cabbage germplasm resources, the selection of new varieties, the breeding of good species, the study of cultivation techniques, and the demonstration and promotion of the germplasm.

E-mail: zhf334480@126.com