Acta Physiologiae Plantarum

, 33:2311

Effects of salt-tolerant rootstock grafting on ultrastructure, photosynthetic capacity, and H2O2-scavenging system in chloroplasts of cucumber seedlings under NaCl stress

  • Ai Zhen
  • Zhilong Bie
  • Yuan Huang
  • Zhixiong Liu
  • Bo Lei
Original Paper

DOI: 10.1007/s11738-011-0771-3

Cite this article as:
Zhen, A., Bie, Z., Huang, Y. et al. Acta Physiol Plant (2011) 33: 2311. doi:10.1007/s11738-011-0771-3

Abstract

Plant growth, photosynthetic parameters, chloroplast ultrastructure, and the ascorbate-glutathione cycle system in chloroplasts of self-grafted and rootstock-grafted cucumber leaves were investigated. Grafted plants were grown hydroponically and were exposed to 0, 50, and 100 mM NaCl concentrations for 10 days. Under NaCl stress, the hydrogen peroxide (H2O2) content in cucumber chloroplasts increased, the chloroplast ultrastructure was damaged, and the gas stomatal conductance, intercellular CO2 concentration, as well as shoot dry weight, plant height, stem diameter, leaf area, and leaf relative water content were inhibited, whereas these changes were less severe in rootstock-grafted plants. The activities of ascorbate peroxidase (APX; EC 1.11.1.11), glutathione reductase (GR; EC 1.6.4.2), and dehydroascorbate reductase (DHAR EC 1.8.5.1) were higher in the chloroplasts of rootstock-grafted plants compared with those of self-grafted plants under 50 and 100 mM NaCl. Similar trends were shown in leaf net CO2 assimilation rate and transpiration rate, as well as reduced glutathione content under 100 mM NaCl. Results suggest that rootstock grafting enhances the H2O2-scavenging capacity of the ascorbate–glutathione cycle in cucumber chloroplasts under NaCl stress, thereby protecting the chloroplast structure and improving the photosynthetic performance of cucumber leaves. As a result, cucumber growth is promoted.

Keywords

Chloroplast ultrastructure Grafting H2O2-scavenging system NaCl Photosynthesis 

Abbreviations

APX

Ascorbate peroxidase

AsA

Reduced ascorbic acid

Ci

Intercellular CO2 concentration

DHA

Dehydroascorbate

DHAR

Dehydroascorbate reductase

GR

Glutathione reductase

Gs

Gas stomatal conductance

GSH

Glutathione

GSSG

Oxidized glutathione

H2O2

Hydrogen peroxide

MDHAR

Monodehydroascorbate reductase

O2·−

Superoxide radicals

OH

Hydroxyl radical

Pn

Leaf net CO2 assimilation rate

Pr

Protein

ROS

Reactive oxygen species

RWC

Leaf relative water content

Tr

Transpiration rate

Copyright information

© Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków 2011

Authors and Affiliations

  • Ai Zhen
    • 1
  • Zhilong Bie
    • 1
  • Yuan Huang
    • 1
  • Zhixiong Liu
    • 1
  • Bo Lei
    • 1
  1. 1.College of Horticulture and Forestry, Huazhong Agricultural University/Key Laboratory of Horticultural Plant Biology, Ministry of EducationWuhanPeople’s Republic of China

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