Increased Fitness of Rice Plants to Abiotic Stress Via Habitat Adapted Symbiosis: A Strategy for Mitigating Impacts of Climate Change

Climate change and catastrophic events have contributed to rice shortages in several regions due to decreased water availability and soil salinization. Although not adapted to salt or drought stress, two commercial rice varieties achieved tolerance to these stresses by colonizing them with Class 2 fungal endophytes isolated from plants growing across moisture and salinity gradients

Pyoderma gangrenosum – a review

Pyoderma gangrenosum (PG) is a rare noninfectious neutrophilic dermatosis. Clinically it starts with sterile pustules that rapidly progress and turn into painful ulcers of variable depth and size with undermined violaceous borders. The legs are most commonly affected but other parts of the skin and mucous membranes may also be involved. Course can be mild or malignant, chronic or relapsing with remarkable morbidity. In many cases PG is associated with an underlying disease, most commonly inflammatory bowel disease, rheumatic or haematological disease and malignancy. Diagnosis of PG is based on history of an underlying disease, typical clinical presentation, histopathology, and exclusion of other diseases that would lead to a similar appearance. The peak of incidence occurs between the ages of 20 to 50 years with women being more often affected than men. Aetiology has not been clearly determined yet. The treatment of PG is a challenge. Randomized, double-blinded prospective multicenter trials for PG are not available. The best documented treatments are systemic corticosteroids and ciclosporin A. Combinations of steroids with cytotoxic drugs are used in resistant cases. The combination of steroids with sulfa drugs or immunosuppressants has been used as steroid-sparing modalities. Anti-tumor necrosis alpha therapy in Crohn's disease showed a rapid response of PG. Skin transplants and the application of bioengineered skin is useful in selected cases as a complement to the immunosuppressive treatment. Topical therapy with modern wound dressings is useful to minimize pain and the risk of secondary infections. Despite recent advances in therapy, the prognosis of PG remains unpredictable

Phylogeny and Biogeography of the Carnivorous Plant Family Sarraceniaceae

The carnivorous plant family Sarraceniaceae comprises three genera of wetland-inhabiting pitcher plants: Darlingtonia in the northwestern United States, Sarracenia in eastern North America, and Heliamphora in northern South America. Hypotheses concerning the biogeographic history leading to this unusual disjunct distribution are controversial, in part because genus- and species-level phylogenies have not been clearly resolved. Here, we present a robust, species-rich phylogeny of Sarraceniaceae based on seven mitochondrial, nuclear, and plastid loci, which we use to illuminate this family's phylogenetic and biogeographic history. The family and genera are monophyletic: Darlingtonia is sister to a clade consisting of Heliamphora+Sarracenia. Within Sarracenia, two clades were strongly supported: one consisting of S. purpurea, its subspecies, and S. rosea; the other consisting of nine species endemic to the southeastern United States. Divergence time estimates revealed that stem group Sarraceniaceae likely originated in South America 44–53 million years ago (Mya) (highest posterior density [HPD] estimate = 47 Mya). By 25–44 (HPD = 35) Mya, crown-group Sarraceniaceae appears to have been widespread across North and South America, and Darlingtonia (western North America) had diverged from Heliamphora+Sarracenia (eastern North America+South America). This disjunction and apparent range contraction is consistent with late Eocene cooling and aridification, which may have severed the continuity of Sarraceniaceae across much of North America. Sarracenia and Heliamphora subsequently diverged in the late Oligocene, 14–32 (HPD = 23) Mya, perhaps when direct overland continuity between North and South America became reduced. Initial diversification of South American Heliamphora began at least 8 Mya, but diversification of Sarracenia was more recent (2–7, HPD = 4 Mya); the bulk of southeastern United States Sarracenia originated co-incident with Pleistocene glaciation, <3 Mya. Overall, these results suggest climatic change at different temporal and spatial scales in part shaped the distribution and diversity of this carnivorous plant clade

Response of Solidago canadensis clones to competition

Transplants of ten Solidago canadensis clones were grown under high and low competition in the field to determine whether clones differed in survival, growth, and reproduction under natural conditions. Transplants had higher probability of survival and flowering and were larger in all measures of size when competition was experimentally reduced. Clones differed in almost all these measures of success, but only when variance among transplants within clones was reduced by excluding transplants that experienced heavy herbivore damage. Differences among clones were more apparent under low competition than under high competition, despite higher coefficients of variation within clones under low competition. Adjusting transplant size for initial size (parent ramet rhizome mass) did not change these results, although clones did differ in parent rhizome mass. All of these results suggest that there is little potential for selection to discriminate among these clones. Despite the strong differences in transplant performance between the competition treatments and among clones, the clones did not differ in competitive ability-almost none of the clone x competition interactions were significant. In addition, the measures of success of each clone were usually positively correlated between the high and low competition treatments, suggesting there were no tradeoffs between performance under high and low competition for these clones.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47776/1/442_2004_Article_BF00378042.pd