There is an immediate need for a high-density genetic map of cotton anchored with fiber genes to facilitate marker-assisted selection (MAS) for improved fiber traits. With this goal in mind, genetic mapping with a new set of microsatellite markers [comprising both simple (SSR) and complex (CSR) sequence repeat markers] was performed on 183 recombinant inbred lines (RILs) developed from the progeny of the interspecific cross Gossypium hirsutum L. cv. TM1 x Gossypium barbadense L. Pima 3-79. Microsatellite markers were developed using 1557 ESTs-containing SSRs (> or = 10 bp) and 5794 EST-containing CSRs (> or = 12 bp) obtained from approximately 14,000 consensus sequences derived from fiber ESTs generated from the cultivated diploid species Gossypium arboreum L. cv AKA8401. From a total of 1232 EST-derived SSR (MUSS) and CSR (MUCS) primer-pairs, 1019 (83%) successfully amplified PCR products from a survey panel of six Gossypium species; 202 (19.8%) were polymorphic between the G. hirsutum L. and G. barbadense L. parents of the interspecific mapping population. Among these polymorphic markers, only 86 (42.6%) showed significant sequence homology to annotated genes with known function. The chromosomal locations of 36 microsatellites were associated with 14 chromosomes and/or 13 chromosome arms of the cotton genome by hypoaneuploid deficiency analysis, enabling us to assign genetic linkage groups (LG) to specific chromosomes. The resulting genetic map consists of 193 loci, including 121 new fiber loci not previously mapped. These fiber loci were mapped to 19 chromosomes and 11 LG spanning 1277 cM, providing approximately 27% genome coverage. Preliminary quantitative trait loci analysis suggested that chromosomes 2, 3, 15, and 18 may harbor genes for traits related to fiber quality. These new PCR-based microsatellite markers derived from cotton fiber ESTs will facilitate the development of a high-resolution integrated genetic map of cotton for structural and functional study of fiber genes and MAS of genes that enhance fiber quality.

Salinity is one of the major environmental factors limiting growth and productivity of rice plants. In this study, the effect of salt stress on phospholipid signaling responses in rice leaves was investigated. Leaf cuts were radiolabeled with 32P-orthophosphate and the lipids extracted and analyzed by thin-layer chromatography, autoradiography and phosphoimaging. Phospholipids were identified by co-migration of known standards. Results showed that 32Pi was rapidly incorporated into the minor lipids, phos-phatidylinositol bisphosphate (PIP2) and phosphatidic acid (PA) and, interestingly, also into the structural lipids phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), which normally label relatively slowly, like phosphatidylcholine (PC) and phosphatidylinositol (PI). Only very small amounts of PIP2 were found. However, in response to salt stress (NaCl), PIP2 levels rapidly (<30 min) increased up to 4-fold, in a time- and dose-dependent manner. PA and its phosphorylated product, diacylglyc-erolpyrophosphate (DGPP), also increased upon NaCl stress, while cardiolipin (CL) levels decreased. All other phospholipid levels remained unchanged. PA signaling can be generated via the combined action of phospholipase C (PLC) and diacylglycerol kinase (DGK) or directly via phospholipase D (PLD). The latter can be measured in vivo, using a transphosphatidylation assay. Interestingly, these measurements revealed that salt stress inhibited PLD activity, indicating that the salt stress-induced PA response was not due to PLD activity. Comparison of the 32P-lipid responses in salt-tolerant and salt-sensitive cultivars revealed no significant differences. Together these results show that salt stress rapidly activates several lipid responses in rice leaves but that these responses do not explain the difference in salt tolerance between sensitive and tolerant cultivars.

The editor of this timely book has assembled a team of highly regarded scientists, over 40 contributors, to describe the latest, up-to-date research, theory and applications of this increasingly important area of science.Renowned experts in the field have contributed chapters that describe and discuss some of the most topical aspects of plant genomics. The book is fully illustrated and chapters include comprehensive reference sections.Essential reading for scientists involved in plant genomics and a recommended volume for everyone involved in plant science.

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The present study was undertaken to investigate the in vitro and the in vivo antioxidant and hepatoprotective effects of Ginkgo biloba leave extracts. Qualitative analysis of different leaves extracts [ethanol 70% (Et), ethyl acetate (EA), and water (W)] revealed the presence of flavonoids, phenolic compounds, saponins, tannins, terpenes, and carbohydrates. The quantitative analysis of the leaves extracts revealed that the Et extract contains the highest amounts of tannins, saponins, flavonoids and phenolic compounds. The EA extract contains higher amounts of flavonoids and phenolic compounds and lower amounts of tannins and saponins compared to the W extract. The in vitro studies revealed that all the Ginkgo biloba leave extracts have a high antioxidant activity. The Et extract showed the highest activity followed by the EA extract then the W extract. Moreover, the in vivo studies revealed that all the Ginkgo biloba leave extracts have hepatoprotective activity, which evidenced by the effect of these extracts on the antioxidant enzymes activities [superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), glutathione-S-transferase (GST)], the liver marker enzymes [alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT)], the lipid peroxidation as well as inhibitory effects on nitric oxide (NO) release. The administration of these extracts significantly restored the elevated activities of the liver marker enzymes, and the antioxidant enzymes, which increase during hepatotoxicity. Also, they inhibit the release of NO. The treatment with the Et extract gave the best results for hepatoprotective effects. Moreover, the administration with this extract did not significantly affect the normal values of blood glucose (BG), total proteins (T.P), total lipids (T.L), total cholesterol (T.C), low and high density lipoprotein cholesterol (LDL-c and HDL-c). From this study it can conclude that the treatment with Ginkgo biloba leave extracts can inhibit the hepatotoxicity without toxic effect.