Microarray-analysis for components of salinity-stress tolerance
Sep 3rd
Microarray-analysis for components of salinity-stress tolerance
Thiourea has been demonstrated to impart salinity-stress tolerance to seedlings of mustard, Brassica juncea. Srivastava et al. perform a genome-wide transcriptome analysis of seeds treated with either salinity, or salinity plus thiourea. They identify 33 genes showing differential expression between the treatments, belonging to different signalling (ABA and other growth regulators, calcium) and effector (antioxidant) components that play crucial roles in salinity stress tolerance.
Talking about an African Green Revolution
Sep 2nd
The African Green Revolution Forum (AGRF) focuses on promoting investments and policy support for driving agricultural productivity and income growth for African farmers … http://agro.biodiver.se/2010/09/talking-about-an-african-green-revolution/
Dating the Pharaohs
Sep 2nd
Image: Jeff Dahl, Wikimedia Commons.
No, not a sensationalist virtual reality TV show for some so-called celebrities seeking to marry into the family of the ancient rulers of Egypt. Rather, work that attempts to ascribe actual dates to the reigns of the Pharaohs who ruled that ancient African former kingdom from about 2650 bc to 1100 bc. Until now, the chronologies for ancient Egypt were based on inferences of reign lengths using written and archaeological evidence. Unfortunately, that gives ‘floating chronologies’, which provide an enduring source of debate amongst scholars of that period. Using radiocarbon measurements from short-lived plants, Christopher Ramsey and colleagues (Science 328: 1554–1557, 2010) have produced a chronology that indicates – amongst other revelations – that the New Kingdom started between 1570 and 1544 bce, earlier than some previous historical estimates (‘Before Current Era’ in case you’re wondering where the extra e came from: http://en.wikipedia.org/wiki/B.C.E.). Whilst it is hoped that the work will settle some long-standing disputes among Egyptologists – e.g. dates of the reigns of such famous Pharaohs as Tutankhamen and Ramses – the work also has relevance to several major religions whose histories have numerous mentions of Egyptian personalities and events. It is also possible that the More >
Nickel hyperaccumulation and systematics of Alysseae
Sep 1st
Nickel hyperaccumulation and systematics of Alysseae
Nickel (Ni) hyperaccumulation is a rare form of physiological specialization shared by a small number of angiosperms growing on ultramafic soils. Molecular phylogenetic analyses by Cecchi et al. reveal that Ni-hyperaccumulation has a double origin in Alysseae. Genetic continuity and strong phenotypic plasticity in the A. murale complex call for a reduction of the number of Ni hyperaccumulator taxa formally recognized.
Cover pictures, transgene stability and cell biology
Sep 1st
Cellular expression of GFP in transgenic potato cells
When growing plants in the field or greenhouse, one is very conscious of seasons and thinking about when to plant, cross and harvest. But as an Editor, it is the ticking of the clock to the next issue that makes the world turn! One particular pleasure is selecting the cover picture: it must be visually appealing, highlight a particularly interesting paper in the issue, and the pictures over the year should reflect the range of research papers we publish. The October cover meets all these criteria particularly well. It shows green fluorescent protein (GFP) in multicellular trichome cells on stems of potato, and relates to the paper (which will be available in early September when the proof corrections have been returned) ”Successive silencing of tandem reporter genes in potato (Solanum tuberosum) over five-years of vegetative propagation” by a group from Charles University in Prague, Eva Nocarova, Zdenek Opatrny and Lukas Fischer. This paper follows the expression of two transgenes, GFP and NPTII, over an extended period of five years, rather than the short period usually used to find expression of transgenes. In 25% of the lines, expression of the genes is silenced, and where this occurs, silencing of the two genes is sequential with the More >
Pollen viability in Mediterranean orchids
Aug 30th
Pollen viability in Mediterranean orchids
Evaluation of pollen viability has generally been confined to a relatively low number of species. Bellusci et al. study five related Mediterranean orchid genera (Anacamptis, Orchis, Dactylorhiza, Ophrys and Serapias) that are characterized by different types of deceptive pollination and find that pollen viabilities of species groups with different deception types have significant differences, with sexually and shelter-deceptive species exhibiting a shorter life span than food-deceptive species. They propose that this relationship can be attributed to the different types of reproductive barriers, pre- or post-zygotic, that characterise Ophrys and Serapias and the food-deceptive species, respectively.
Genetic relationships between sympatric and allopatric Casearia
Aug 27th
Genetic relationships between sympatric and allopatric Casearia
Casearia sylvestris var. sylvestris inhabits humid, dense forests, while var. lingua is restricted to xeric habitats, yet despite differences in morphology and habitat preference, intermediate forms exist in transitional environments, complicating the delimitation of the taxa. Cavallari et al. examine nine microsatellite markers and conclude that the two C. sylvestris varieties are relatively independent biological units, rather than representing the genetic continuum of a single species. Evidence for the existence of putative hybrid zones between these two varieties is also considered.
The Genetics Behind Evolution
Aug 27th
Highlight Annals of Botany cover
Over the years, hundreds of papers have been published describing the genetic changes that occur during evolution of plants, and the differences evident between individual species. An equally high number of papers has been published about the definition of species, their separation and naming. Many have joined discussions of where and why new species form – by reproductive barriers or island colonization for example. But only now are we realizing that there is a strong genetic component to these events: speciation does not ‘just happen’.
We plan most highlight issues of Annals of Botany a year of more in advance. But the seven papers for the September Highlight issue, “Genes in evolution”, was just because these papers were all submitted around the same time. This shows that the control of diversity and speciation is a really hot-topic, where advances unforseen a year ago are now taking place – and the implications are widespread from the consequences of changing climate on natural ecosystems, to the breeding and selection approaches for new and improved crops.
The review by Rieseberg and Blackman (2010) identifies no less than 41 genes that can lead to reproductive isolation of populations. Interestingly, the genes are very diverse, and More >
How bad is science reporting?
Times Higher Education asks if there is problem with science reporting and if anything can be done to make it better. (link)
Tetrad shape and aperture pattern ontogeny in pollen
Aug 25th
Tetrad shape and aperture pattern ontogeny in pollen
Patterns of male cytokinesis are suspected to play a role in the diversity of aperture patterns found in pollen grains of angiosperms. By comparing two eudicots, Epilobium roseum and Paranomus reflexus, that exhibit intra-individual variation in aperture number, Abert et al. demonstrate that the positions of apertures are determined by the way additional callose is deposited once the cytoplasms are severed in cytokinesis. The recorded variation in tetrad shape is correlated with variations in aperture pattern, demonstrating the role of cell partitioning in aperture pattern ontogeny.
