Synteny and identification of candidate genes underlying QTL controlling stomatal traits

 

Use of synteny to identify candidate genes underlying QTL controlling stomatal traits in faba bean (Vicia faba L.)

by Khazaei H., O’Sullivan D., Silanpää M. J., Stoddard F. L. (2014)

Hamid Khazaei, University of Saskatchewan

Donal O’Sullivan, University of Reading

Mikko J Sillanpää, University of Oulu

Frederick L. Stoddard, University of Helsinki

in Theoretical and Applied Genetics 127(11) · September 2014 – DOI: 10.1007/s00122-014-2383-y –

https://www.researchgate.net/publication/265342275_Use_of_synteny_to_identify_candidate_genes_underlying_QTL_controlling_stomatal_traits_in_faba_bean_Vicia_faba_L

Key message

We have identified QTLs for stomatal characteristics on chromosome II of faba bean by applying SNPs derived from Medicago truncatula, and have identified candidate genes within these QTLs using synteny between the two species.

Abstract

Faba bean (Vicia faba L.) is a valuable food and feed crop worldwide, but drought often limits its production, and its genome is large and poorly mapped. No information is available on the effects of genomic regions and genes on drought adaptation characters such as stomatal characteristics in this species, but the synteny between the sequenced model legume, Medicago truncatula, and faba bean can be used to identify candidate genes.

A mapping population of 211 F5 recombinant inbred lines (Mélodie/2 × ILB 938/2) were phenotyped to identify quantitative trait loci (QTL) affecting stomatal morphology and function, along with seed weight, under well-watered conditions in a climate-controlled glasshouse in 2013 and 2014. Canopy temperature (CT) was evaluated in 2013 under water-deficit (CTd).

In total, 188 polymorphic single nucleotide polymorphisms (SNPs), developed from M. truncatula genome data, were assigned to nine linkage groups that covered ~928 cM of the faba bean genome with an average inter-marker distance of 5.8 cM. 15 putative QTLs were detected, of which eight (affecting stomatal density, length and conductance and CT) co-located on chromosome II, in the vicinity of a possible candidate gene—a receptor-like protein kinase found in the syntenic interval of M. truncatula chromosome IV.

A ribose-phosphate pyrophosphokinase from M. truncatula chromosome V, postulated as a possible candidate gene for the QTL for CTd, was found some distance away in the same chromosome.

These results demonstrate that genomic information from M. truncatula can successfully be translated to the faba bean genome.

Stomatal characteristics and the environment

 

Do faba bean (Vicia faba L.) accessions from environments with contrasting seasonal moisture availabilities differ in stomatal characteristics and related traits?

by Khazaei H., Street K., Santanen A., Bari A., Stoddard F. L. (2013)

Hamid Khazaei, University of Saskatchewan

Arja Santanen, University of Helsinki

Frederick L. Stoddard, University of Helsinki

in Genet. Resour. Crop Evol. (2013) 60: 2343. – doi:10.1007/s10722-013-0002-46363 –

http://link.springer.com/article/10.1007%2Fs10722-013-0002-4

Abstract

Drought is a major constraint to faba bean (Vicia faba L.) production, and there are many mechanisms by which leaves can regulate water loss. Our primary objective was to test if the origin of the faba bean accessions, from drought-prone and non-drought-prone environments, was associated with differences in measurable aspects of stomatal morphology and physiology related to water use.

Two sets, each consisting of 201 faba bean accessions, were chosen from environments with contrasting seasonal moisture profiles following the focused identification of germplasm strategy (FIGS), and then screened under well watered conditions. From these, two subsets of 10 accessions each were chosen to test for differences in response to drought.

Parameters related to stomatal function and water status were measured. The dry-adapted set had bigger stomata, higher leaf relative water content (LRWC) and cooler leaves under well watered conditions. Stomatal density and stomatal area per unit area of leaflet were negatively correlated with gas exchange parameters and positively correlated with intrinsic water use efficiency.

Drought caused stomatal densities to increase in the dry set while stomatal length decreased in both sets. The moisture deficit was sufficient to decrease gas exchange in both sets to similar levels, but the dry-adapted set maintained warmer leaves and a higher LRWC that showed no significant correlations with leaf morphology or gas exchange, demonstrating more effective stomatal regulation.

The results also support that collection site data from the environment where genetic resources are collected can be used as indicators of adaptive traits in an herbaceous annual species.

Stomatal density in coconut

 

Stomatal density in varieties and from of the coconut.

by Manthriratna M.A.P.P., Sambasivam S. (1974)

Coconut Research Institute, Lunuwila, Sri Lanka.

in Ceylon Coconut Q. 25: 105-108. –

http://dl.nsf.ac.lk/bitstream/handle/1/19964/COCOQ-25(3-4)-105.pdf?sequence=2

SUMMARY

An assessment of stomatal densities of varieties and forms of the coconut palm (Cocos nucifera L.), indicates that this may be a varietal characteristic.

Variations due to the environment are negligible. All three colour forms of the self-pollinating nana variety have more stomata per unit area of leaf surface than the varieties typica and aurantiaca.

Stomatal density may be of use in identifying typica x pumila F1 hybrids.

Stomata in barley

 

Frequency and distribution of stomata in barley.

by Miskin K. E., Rasmusson D. C. (1970)

Dep. Agron. Univ. Minnesota, St Paul.

in Crop Sci. 10(5): 575-578. – doi:10.2135/cropsci1970.0011183X001000050038x –

https://dl.sciencesocieties.org/publications/cs/abstracts/10/5/CS0100050575?access=0&view=pdf

Abstract :

Stomatal frequency on the lower surface of the flag leaves of 649 cultivars from the World Collection of Barley, Hordeum vulgate L., ranged from 36 to 98 stomata mm⁻⁵ with a mean of 64. Differences in stomatal frequency observed in the field were confirmed by a greenhouse experiment involving 50 cultivars. Among 20 cultivars examined for stomatal size, mean guard cell length varied from 41 to 56 μ. A negative correlation, –.86, was obtained between stomatal frequency and size.

Stomatal frequencies of several cultivars decreased progressively from the flag to the lower leaves, with the flag leaf having approximately twice as many stomata mm^-2 as the basal leaves. Stomatal frequencies on the lower and upper surface of the flag leaves were similar. Stomata were not found on the lemma, and on the awn they were limited to two rows on the outer face. A single row of stomata extended down each side of the crease of the palea. Increased light intensity resulted in higher stomatal frequency, whereas temperature variations affected frequency very little.

 

A film of clear nail polish to study stomata

 

Convenient method for studying grass leaf epidermis.

by Hilu K. W., Randall J. L. (1984)

Khidir Hilu, Virginia Polytechnic Institute and State University

Randall J. L.

in Taxon,33(3): 413-415. – DOI: 10.2307/1220980 –

https://www.researchgate.net/publication/271802053_Convenient_Method_for_Studying_Grass_Leaf_Epidermis

Abstract

Leaf epidermis of grasses is structurally elaborate and quite important in modern systematics of the Poaceae.

Available techniques used in preparing leaf epidermis for microscopic studies are time-consuming and do not always produce adequate preparations. A simple and convenient technique is proposed in this paper which requires the application of a film of clear nail polish directly to the leaf surface.

The impressions left on the polish film after drying produce an excellent detailed image of the epidermis. This technique is also applicable to other plant families.

Stomata in Liliaceae

Photo credit: Google

Smilax glauca

Stomatal structures as an aid to the taxonomy of Liliaceae.

by Gopal B. V., Raza S. H. (1992)

in Asian J. Plant Sci. 4(2): 51-56. –

https://eurekamag.com/research/009/460/009460139.php

Abstract

Structure of stomata is described on mature leaves of 11 species of Liliaceae (Sensu Bentham and Hooker, 1965).

Anomocytic, paracytic and tetracytic are the predominant types of stomata observed.

Based on the occurrence of the predominant type of stomata, the present investigation endeavours to draw certain conclusions on the systematic position of some genera in the family. Monogeneric status for Ruscus and Smilax is supported by the present study.

Estimation of stomatal apertures

 

Accurate estimation of stomatal aperture from silicone rubber impressions

by Weyers J. D. B., Johansen L. G. (1985)

Jonathan D. Weyers

Liv G. Johansen

in New Phytologist Volume 101, Issue 1, 109–115 – DOI: 10.1111/j.1469-8137.1985.tb02820.x –

http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1985.tb02820.x/full

Summary

The potential of low viscosity silicone-based impression material for measuring stomatal aperture on intact leaves was investigated.

It was found that the probability of successful replication of Commelina communis L. stomata depended on the width of the stomatal pores. The wider pores in a sample were more likely to be measured, so the resulting estimated mean was an overestimate of the true mean. This bias in estimates of stomatal aperture from impressions was studied and quantified.

A transformation is described which was used to adjust apparent aperture measurements from impressions to give more accurate estimates of stomatal apertures on intact leaves of C. communis. Maximum absolute errors due to the bias usually occurred at apparent apertures on impressions of between 2 and 5 μm but were proportionally greatest below 3μm, where they often exceeded 40%. At a given aperture, the error depended upon the dispersion of the stomatal apertures about their mean and was greatest when this was large.

Stomatal aperture as a characteristic response to environmental and experimental conditions

 

The problem of variability in stomatal responses, particularly aperture variance, to environmental and experimental conditions

by Spence R. D. (1987)

Richard D. Spence

in New Physiol. 107(2): 303 – 315. – DOI: 10.1111/j.1469-8137.1987.tb00182.x – 

http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1987.tb00182.x/full

Summary

The extreme variability observed in stomatal responses to identical treatments has hindered the drawing of specific conclusions about how stomata respond to environmental factors and the mechanisms that drive these responses.

This review considers stomatal aperture as a characteristic response and the ramifications of the observed within-sample variance in aperture. In the wake of past research efforts, the efficacy of experimental techniques developed to observe stomatal aperture is reviewed, environmental, morphological and physiological factors that are thought to contribute to aperture variance are discussed, and the desirability of implementing procedures to reduce aperture variance is assessed. By taking into account these considerations, researchers may be better able to plan their future efforts.

Variation in stomata in Commelina communis leaves (monocots)

 

Variation in stomatal characteristics over the lower surface of Commelina communis leaves.

by Smith S., Weyers J. D. B., Berry W. G. (1989)

Jonathan D. B. Weyers,

Department of Biological Sciences, University of Dundee, U.K.

in Plant Cell Env. 12, 653-659. – DOI: 10.1111/j.1365-3040.1989.tb01234.x – 

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.1989.tb01234.x/full

Abstract

The silicone rubber impression technique was used to measure stomatal apertures in 9 mm² sampling areas covering the entire lower surface of leaves of Commelina communis L. The data were analysed using a computer program which produced ‘iso-aperture’ contours illustrating local differences in mean stomatal aperture.

Little consistency was seen in the iso-aperture patterns among sampling times, although the stomata were always relatively closed at the leaf tip and base. When stomata in the middle of the lamina were open, those near to the leaf margin tended to be relatively closed. In places, gradients of mean stomatal aperture were as high as 1 μm mm⁻¹.

Measurements along a transect across the lower epidermis revealed no correlation of stomatal aperture with the presence of major veins in the mesophyll tissue. Variation in guard-cell size and stomatal frequency on the lower leaf surface was also analysed.

The guard cells were smallest and the stomata more frequent near to the leaf margins. The significance of the results is discussed in relation to measurements of leaf conductance and models of stomatal function.

 

Stomata in grasses of the Andropogoneae (Poaceae)

 

Foliar epidermal studies as an aid to the identification of grasses of tribe Andropogoneae (Poaceae) from Potohar region of Pakistan

by Nazir A., Khan M. A., Ahmad F., Ullah K., Shah A. (2013)

ABDUL NAZIR1 , MIR AJAB KHAN1 , FAROOQ AHMAD3, Kifayat Ullah1 AND AMIN SHAH4

1 Department of Plant Sciences, Quaid-i-Azam University Islamabad, Pakistan

3 Department of Botany, University of Agriculture Faisalabad, Pakistan

4 Department of Botany, University of Sargodha, Sargodha Pakistan

Abdul Nazir, COMSATS Institute of Information Technology – Islamabad, Pakistan

Mir Khan, Quaid-i-Azam University, Islamabad

 

in Pak. J. Bot., 45(SI): 235-241. –

http://www.pakbs.org/pjbot/PDFs/45(S1)/32.pdf

Abstract

In the present investigations, 13 species of grasses belonging to 10 genera of tribe Andropogoneae (Poaceae) were collected from the Potohar region of Pakistan and their leaf epidermal studies were carried out.

The leaf epidermal studies showed that all the species have paracytic stomata, with dumb bell shaped guard cells, except Heteropogon contortus and Cymbopogon jwarancusa in which guard cells are straight in the middle.

Different types of subsidiary cells such as high dome shaped, triangular shaped or low dome shaped subsidiary cells are observed. The difference in shape of subsidiary cells can be used to differentiate problematic species such as genus Bothriochloa from Dicanthium, as these genera look similar morphologically.

Diversity in shapes of silica bodies is observed in the species of this tribe, which is valuable for identification. Silica bodies are cross shaped, dumb bell shaped or intermediate between cross and dumb bell shaped.

Bicelled microhairs of panicoid type are present in all the species except Euloliopsis binata in which microhairs are absent. Microhairs are rounded in all species except Cymbopogon jawarancusa and Heteropogon contortus.

The studies revealed that different leaf epidermal characters such as shape of subsidiary cells, silica bodies, presence or absence of microhairs, macrohairs and rounded papillae are valuable in the identification of grasses at the specific and generic level of the tribe.