Reflectance and cyclic electron flow as an indicator of drought stress in cotton (Gossypium hirsutum).

Abstract

The response and the functioning of the photosynthetic machinery of cotton, Gossypium hirsutum during water stress was studied by leaf optical properties, linear (ETRII) and cyclic electron flow (CEF) and chlorophyll a fluorescence. We observed that in G. hirsutum, during water limitation, Chlorophyll b showed the best correlation with reflectance at 731 nm and is a better indicator of drought. Fv /Fm was observed to be very insensitive to mild water stress. However, during severe water stress the leaves exhibit considerable inhibition in Fv /Fm and an increase in anthocyanin levels by about 20-fold. CEF was very responsive to mild water stress. The mild drought stress caused large decrease in the ability of the leaves to utilize the light energy. Photosystem I and photosystem II is protected from photoinhibition by high CEF and nonphotochemical quenching under mild water stress. While during severe drought stress, linear electron flow showed a sharp decrease in comparison to CEF. CEF play a major role in G. hirsutum leaves during mild as well as under severe water stress condition and is thus a good indicator of water stress.

• Authors: Ruchi Singh, Jishnu Naskar, Uday V Pathre, Pramod A Shirke
• Journal: Photochemistry and photobiology (Photochem Photobiol) 2014 May-Jun Vol. 90 Issue 3 Pg. 544-51 ISSN: 1751-1097 [Electronic] United States
• PMID: 24246098 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2013 The American Society of Photobiology.

Chemical References

• Anthocyanins
• Photosystem I Protein Complex
• Photosystem II Protein Complex

Topics

• Anthocyanins (metabolism)
• Droughts
• Electrons
• Gossypium (metabolism, physiology)
• Photosynthesis
• Photosystem I Protein Complex (physiology)
• Photosystem II Protein Complex (physiology)
• Plant Leaves (metabolism)