Stomatal dynamics under fluctuating light is closely related to drought resistance

 

 

Rapid stomatal response to fluctuating light: an under-explored mechanism to improve drought tolerance in rice

by Qu M., Hamdani S., Li W., Wang S., Tang J., Chen Z., Song Q., Li M., Zhao H., Chang T., Chu C., Zhu X. (2016)

by Mingnan Qu ^A, Saber Hamdani ^A, Wenzhen Li ^C, Shimei Wang ^B, Jiuyou Tang ^C,Zhuo Chen ^C, Qingfeng Song ^A, Ming Li ^A, Honglong Zhao ^A, Tiangen Chang ^A,Chengcai Chu ^C and Xinguang Zhu ^{A D}

^A CAS-Key Laboratory for Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Room 106, Physiology Building, 320 Yueyang Road, Shanghai 200031, China.
^B Anhui Agricultural Academy of Sciences, 40 Nongke South Road, Hefei, Anhui 230031, China.
^C The State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, 1 Beichen South road, Chinese Academy of Sciences, Beijing 100101, China.
^D Corresponding author. Email: zhuxinguang@picb.ac.cn

in Functional Plant Biology – http://dx.doi.org/10.1071/FP15348

Abstract

Light inside a canopy constantly fluctuates. Under fluctuating light (FL) conditions, stomatal conductance and photosynthetic rate constantly change.

In this study, we explored whether this dynamics of stomata movements upon FL influenced the water use efficiency of rice in the field. We used a USDA-curated rice mini-core diversity panel consisting of 204 worldwide distributed accessions.

A priori model on dynamic stomatal response to FL was utilised to identify kinetic parameters describing the stomatal delays during the closing (τ_cl) and the opening (τ_op) phase.

Result showed that τ_cl had a larger variation than τ_op across the mini-core panel. τ_cl was negatively correlated with water use efficiency (WUE) related traits, stem diameter, grain weight per tiller and heading time, but positively correlated with maximum annual temperature, carbon assimilation related traits and biomass (P < 0.05).

We further showed a strong correlation of τ_cl with the relative decrease of biomass under drought in 14 accessions with different τ_cl.

We discussed the adjustment of stomatal conductance under fluctuating light in light of the trade-off between optimising CO₂ uptake and optimising water saving.

This study suggests that stomatal dynamics under fluctuating light is closely related to drought resistance and hence detailed study is needed to enable its application in breeding drought tolerance in rice.