Reduction of photosynthesis under P deficiency is mainly caused by the decreased CO2 diffusional capacities in wheat (Triticum aestivum L.)

Yu Shu; Guanjun Huang; Qiangqiang Zhang; Shaobing Peng; Yong Li

doi:10.1016/j.plaphy.2023.107680

Reduction of photosynthesis under P deficiency is mainly caused by the decreased CO₂ diffusional capacities in wheat (Triticum aestivum L.)

Plant Physiol Biochem. 2023 May:198:107680. doi: 10.1016/j.plaphy.2023.107680. Epub 2023 Apr 4.

Authors

Yu Shu¹, Guanjun Huang², Qiangqiang Zhang³, Shaobing Peng⁴, Yong Li⁵

Affiliations

¹ National Key Laboratory of Crop Genetic Improvement, Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China. Electronic address: 1617368317@qq.com.
² Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, School of Agricultural Sciences, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China. Electronic address: 2019301010004@webmail.hzau.edu.cn.
³ National Key Laboratory of Crop Genetic Improvement, Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China. Electronic address: 275252951@qq.com.
⁴ National Key Laboratory of Crop Genetic Improvement, Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China. Electronic address: speng@mail.hzau.edu.cn.
⁵ National Key Laboratory of Crop Genetic Improvement, Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China. Electronic address: liyong@mail.hzau.edu.cn.

PMID: 37031546
DOI: 10.1016/j.plaphy.2023.107680

Abstract

Phosphorus is one of the most important essential mineral elements for plant growth and development. It has been widely recognized that phosphorus deficiency can lead to the significant declines in leaf photosynthetic rate and leaf area. However, the internal mechanism associated with the leaf anatomical traits has not been well understood. In present study, a hydroponic experiment was conducted to study the effect of phosphorus deficiency on leaf growth and photosynthesis in Jimai 22 (JM22, Triticum aestivum L.) and Suk Landarace 26 (SL26, Triticum aestivum L.). With the decrease in phosphorus concentration, leaf photosynthetic rate and leaf area in SL26 and JM22 all decreased significantly, but the decrease in leaf area occurred earlier than that in leaf photosynthetic rate. The thresholds of phosphorus concentration to maintain a high photosynthesis were 145.5 and 138.7 mg m^-2, respectively, in SL26 and JM22; and they were 197.5 and 212.0 mg m^-2, respectively, for leaf growth. The decrease in leaf photosynthetic rate under low P conditions was mainly caused by the lowered stomatal conductance and mesophyll conductance, and to a less extent by the decrease in biochemical capacities. The decrease in stomatal conductance was attributed to the smaller vascular bundle area, xylem conduits area and the lower leaf hydraulic conductance. However, the reduction in mesophyll conductance was not related to either the cell wall thickness or the development of chloroplast.

Keywords: Leaf anatomical structure; Leaf growth; Mesophyll conductance; Phosphorus; Stomatal conductance.

MeSH terms

Carbon Dioxide
Mesophyll Cells
Phosphorus
Photosynthesis
Plant Leaves
Plant Stomata*
Triticum*

Substances

Carbon Dioxide
Phosphorus