High salicylic acid concentration alters the electron flow associated with photosystem II in barley

Acta Agriculturae Slovenica

Ghader Habibi¹  Atousa Vaziri¹ 

[1] Department of Biology, Payame Noor University (PNU), IRAN

关键词: photosynthetic pigments;    photosynthetic electron flow;    Hordeum vulgare ‘Bahman’;    OJIP transient flourescence;    salicylic acid;   

DOI  :  10.14720/aas.2017.109.2.22

学科分类：农业科学（综合）

来源: Univerza v Ljubljani * Biotehniska Fakulteta / University of Ljubljana * Biotechnical Faculty

【 摘 要 】

In this study, the effects of exogenously applied salicylic acid (0.5 and 5 mM SA) on the rates of photosystem II (PSII) activity was analysed in 4-week-old barley ( Hordeum vulgare‘ Bahman’ ) seedlings using chlorophyll (Chl)afluorescence transient ( OJIP ) measurements. No evident changes in Chl and carotenoid contents as well as chlorophyll fluorescence transient curves were observed in either of the studied concentrations after 24 h of SA application. After 5 d, low SA concentration (0.5 mM) increased PSII activity, Chlband carotenoid contents in barley seedlings. In contrary, 5 days after 5 mM SA treatment, the maximal quantum efficiency of PSII ( Fv / Fm ) and the Performance Index (PI ABS ), as an indicator of PSII structure and functioning, were significantly decreased. This lowerFv / Fmand PI ABScoupled with lower levels of Chlband carotenoids, and lower values of photosynthetic electron transport chain components including the electron transport flux ( φ E o ) and the inferred oxygen evolving complex activity ( Fv / Fo ). By monitoring the chlorophyllafluorescence rise kinetics, from the initial “ O ” level to the “ P ” (the peak) level, a dramatic increase in “ OJ ” phase was detected, which coincides with an increased photo-reduction of Q Aas a result of blockage of electron flow. This study provided the evidence that the high concentration of SA induced damage to different sites of the PSII.

【 授权许可】

CC BY-NC-ND