Effects of drought stress on photosynthetic physiological characteristics, leaf microstructure, and related gene expression of yellow horn

ABSTRACT

Yellow horn grows in northern China and has a high tolerance to drought and poor soil. Improving photosynthetic efficiency and increasing plant growth and yield under drought conditions have become important research content for researchers worldwide. Our study goal is to provide comprehensive information on photosynthesis and some candidate genes breeding of yellow horn under drought stress. In this study, seedlings’ stomatal conductance, chlorophyll content, and fluorescence parameters decreased under drought stress, but non-photochemical quenching increased. The leaf microstructure showed that stomata underwent a process from opening to closing, guard cells from complete to dry, and surrounding leaf cells from smooth to severe shrinkage. The chloroplast ultrastructure showed that the changes of starch granules were different under different drought stress, while plastoglobules increased and expanded continuously. In addition, we found some differentially expressed genes related to photosystem, electron transport component, oxidative phosphate ATPase, stomatal closure, and chloroplast ultrastructure. These results laid a foundation for further genetic improvement and deficit resistance breeding of yellow horn under drought stress.

KEYWORDS:

• Yellow horn
• drought stress
• photosynthetic
• microstructure
• transcription factors

Disclosure statement

No potential conflict of interest was reported by the authors.

Authorship

The authors confirm their contribution to the paper: study conception and design: Jinping. G; data collection: Fang. H; analysis and interpretation of results: Fang. H; draft manuscript preparation: Fang. H; supervision: Yunxiang. Z. All authors reviewed the results and approved the final version of the manuscript.

Compliance with ethical standards

The authors declare that this article complies with the journal’s standards.

Nomenclature

RWC	=	Relative water content
gs	=	Stomatal conductance
SPAD	=	Chlorophyll value
Fv/Fm	=	The maximal photochemical efficiency of PSII
ETR	=	Linear electron transport rate
NPQ	=	Non-photochemical quenching
RUBP	=	1,5-diphosphate ribulose oxygenase
PG	=	Plastoglobules
PQ	=	Plastoquinone
QA	=	Primary PS II quinone electron acceptor
ABS/RC	=	Absorption flux per reaction center
DIo/RC	=	Dissipated energy flux per RC (at t = Fo)
ETo/RC	=	Electron transport flux per RC (at t = Fo)
φPo	=	Maximum quantum yield of primary photochemistry
φEo	=	Quantum yield for electron transport (at t = Fo)
φO	=	Probability that a trapped exciton moves an electron into the electron transport chain beyond QA (at t = Fo)
φO	=	Probability that a trapped exciton moves an electron into the electron transport chain beyond QA (at t = Fo)
VJ	=	Relative variable fluorescence at the J-step
VI	=	Relative variable fluorescence at the I-step
Sm	=	Normalized total complimentary area
ABS/CSm	=	Absorption flux per CS (at t = Fm)
TRo/CSm	=	Trapped energy flux per CS (at t = Fm)
DIo/CSm	=	Dissipated energy flux per CS (at t = Fm)
ETo/CSm	=	Electron transport flux per CS (at t = Fm)
PIabs	=	Performance index on absorption basis

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15592324.2023.2215025

Additional information

Funding

This research was funded by Shanxi Key Laboratory of Cultivation & Development on Functional oil trees in northern China and the Conservation of Fine Seedlings of Xanthoceras sorbifolium Bunge and Clonal Breeding of Excellent Varieties.