Work

Effects of low potassium stress on leaf photosynthesis and sucrose metabolism in sesame seedling stage

Year: 2026

Type: article

Abstract: Objective To explore the response mechanisms of photosynthesis and leaf sucrose metabolism in sesame to low potassium（K）stress. Method The hydroponic experiment was conducted with the low-K sensitive cultivar Zhongzhi No.9（ZZ9）and low-K tolerant WZM6 selected as the materials.The leaf net photosynthetic rate（Pn），stomatal conductivity（Gs），and the activities of 1，5-ribulose diphosphate carboxylase（Rubisco），sucrose phosphate synthase（SPS），sucrose acid invertase（SAI），sucrose synthase（SuSy）as well as the content of soluble sugar，soluble protein，sucrose，starch of sesame seedlings were analyzed in response to low K and normal K conditions. Result Compared with the normal K treatment，the Pn，Gs，and activities of Rubisco，SPS，SuSy and soluble protein content of the ZZ9 cultivar significantly decreased by 22.0%，18.2%，40.0%，24.0%，7.9% and 25.5% respectively；while the contents of soluble sugar，sucrose，starch and SAI activity in leaves significantly increased by 110.0%，61.2%，38.1% and 8.1% respectively.The WZM6 cultivar showed smaller variations in leaf photosynthetic capacity and sucrose metabolism-related indicators under low K stress.Additionally，the absolute values of the stress coefficients of various physiological indicators of the low K-sensitive ZZ9 cultivar were higher than those of the low K-tolerant WZM6 cultivar，indicating that ZZ9 was more severely affected by low K stress. Conclusion Low K stress affects the growth and development of sesame seedlings by weakening photosynthesis，hindering the transport of photosynthetic products and interfering with the carbon metabolism pathway.The activities of sucrose metabolic enzymes，photosynthetic capacity and osmotic adjustment substances are more sensitive to K nutrition levels in ZZ9，while these indicators were minor changed by low-K stress in WZM6.

Source: ACTA AGRICULTURAE UNIVERSITATIS JIANGXIENSIS

DOI: 10.3724/aauj.2026004

Authors: Ziwei WANG, Biqing ZHANG, Sheng FANG

Institutions: Huazhong Agricultural University, Jiangxi Agricultural University

Language: English

Topic: Plant nutrient uptake and metabolism

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: bronze

Funder: National Natural Science Foundation of China