Stomatal behavior and traits

 

Linking stomatal traits and expression of slow anion channel genes HvSLAH1 and HvSLAC1 with grain yield for increasing salinity tolerance in barley

by Liu X., Mak M., Babla M., Wang F., Chen G., Veljanoski F., Wang G., Shabala S., Zhou M., Chen Z.-H. (2014)

in Front. Plant Sci.,5: 634, 25 November 2014 | http://dx.doi.org/10.3389/fpls.2014.00634

Soil salinity is an environmental and agricultural problem in many parts of the world. One of the keys to breeding barley for adaptation to salinity lies in a better understanding of the genetic control of stomatal regulation.

We have employed a range of physiological (stomata assay, gas exchange, phylogenetic analysis, QTL analysis), and molecular techniques (RT-PCR and qPCR) to investigate stomatal behavior and genotypic variation in barley cultivars and a genetic population in four experimental trials.

A set of relatively efficient and reliable methods were developed for the characterization of stomatal behavior of a large number of varieties and genetic lines. Furthermore, we found a large genetic variation of gas exchange and stomatal traits in barley in response to salinity stress. Salt-tolerant cultivar CM72 showed significantly larger stomatal aperture under 200 mM NaCl treatment than that of salt-sensitive cultivar Gairdner.

Stomatal traits such as aperture width/length were found to significantly correlate with grain yield under salt treatment. Phenotypic characterization and QTL analysis of a segregating double haploid population of the CM72/Gairdner resulted in the identification of significant stomatal traits-related QTLs for salt tolerance. Moreover, expression analysis of the slow anion channel genes HvSLAH1 and HvSLAC1 demonstrated that their up-regulation is linked to higher barley grain yield in the field.

Read the full article: Frontiers in Plant Science

Stomatal characteristics, tissue ion relations, and salinity tolerance

 

Linking osmotic adjustment and stomatal characteristics with salinity stress tolerance in contrasting barley accessions

by Zhu M., Zhou M., Shabala L., Shabala S. (2015)

in Functional Plant Biology, 42, (3) pp. 252-263. ISSN 1445-4408 (2015)

Abstract

Salinity tolerance is a complex trait – both physiologically and genetically – and the issue of which mechanism or trait has bigger contribution towards the overall plant performance is still hotly discussed in the literature.

In this work, a broad range of barley (Hordeum vulgare L. and Hordeum spontaneum L.) genotypes contrasting in salinity stress tolerance were used to investigate the causal link between plant stomatal characteristics, tissue ion relations, and salinity tolerance. In total, 46 genotypes (including two wild barleys) were grown under glasshouse conditions and exposed to moderate salinity stress (200 mM NaCl) for 5 weeks. The overall salinity tolerance correlated positively with stomata density, leaf K⁺ concentration and the relative contribution of inorganic ions towards osmotic adjustment in the shoot. At the same time, no correlation between salinity tolerance and stomatal conductance or leaf Na⁺ content in the shoot was found. Taken together, these results indicate the importance of increasing stomata density as an adaptive tool to optimise efficiency of CO₂ assimilation under moderate saline conditions, as well as benefits of the predominant use of inorganic osmolytes for osmotic adjustment in barley. Another finding of note was that wild barleys showed rather different strategies dealing with salinity, as compared with cultivated varieties.

See the text: UTAS