Cucumber (Cucumis sativus L.), a widely cultivated crop, has originated from Eastern Himalayas and secondary domestication regions includes highly divergent climate conditions e.g. temperate and subtropical. We wanted to uncover adaptive genome differences between the cucumber cultivars and what sort of evolutionary molecular mechanisms regulate genetic adaptation of plants to different ecosystems and organism biodiversity. Here we present the draft genome sequence of the Cucumis sativus genome of the North-European Borszczagowski cultivar (line B10) and comparative genomics studies with the known genomes of: C. sativus (Chinese cultivar – Chinese Long (line 9930)), Arabidopsis thaliana, Populus trichocarpa and Oryza sativa. Cucumber genomes show extensive chromosomal rearrangements, distinct differences in quantity of the particular genes (e.g. involved in photosynthesis, respiration, sugar metabolism, chlorophyll degradation, regulation of gene expression, photooxidative stress tolerance, higher non-optimal temperatures tolerance and ammonium ion assimilation) as well as in distributions of abscisic acid-, dehydration- and ethylene-responsive cis-regulatory elements (CREs) in promoters of orthologous group of genes, which lead to the specific adaptation features. Abscisic acid treatment of non-acclimated Arabidopsis and C. sativus seedlings induced moderate freezing tolerance in Arabidopsis but not in C. sativus. This experiment together with analysis of abscisic acid-specific CRE distributions give a clue why C. sativus is much more susceptible to moderate freezing stresses than A. thaliana. Comparative analysis of all the five genomes showed that, each species and/or cultivars has a specific profile of CRE content in promoters of orthologous genes. Our results constitute the substantial and original resource for the basic and applied research on environmental adaptations of plants, which could facilitate creation of new crops with improved growth and yield in divergent conditions.
Defined changes in the cell wall directed by many proteins accompany every morphogenetic process in plants. Xyloglucan endotransglucosylase/hydrolase proteins (XTH; EC 2.4.1.207) have the potential to modify the hemicellulose matrix within the cell wall. Cs-XTH1 and Cs-XTH3 genes, which encode XTH proteins, were found among numerous genes that are differentially expressed after the induction of cucumber somatic embryogenesis. The expression of these genes increased during somatic embryogenesis. The Cs-XTH1 gene was localized on the second chromosome near the centromere region, whereas Cs-XTH3 was found in the middle of the fifth chromosome's longer arm. Northern blot hybridization showed that both genes were preferentially expressed in roots. We also observed higher accumulation of both transcripts in somatic embryos than in the proembryogenic mass. The localization of mRNA by in situ hybridization revealed that the Cs-XTH1 transcripts were largely accumulated in the presumptive cotyledon primordia of somatic embryos. The XTH gene family consists of a number of genes with a high degree of structural similarity. Screening a cucumber genomic library has identified other members of this gene family. The intron/exon structure, sequence similarities and the close chromosomal distance between some members suggest their common evolutionary origin. The involvement of XTH-related genes in somatic embryo formation is discussed.
Effects of the five macro-components and sucrose in half strength MS (1/2 MS) agar medium on red -color pigmentation were studied in the plant bodies of Dionaea muscipula and Drosera spathulata generated from multiple shoots in vitro. In 1/2 MS agar medium modified with 10.31 mM NH4NO3 and 9.40 mM KNO3 and supplemented with 0.75 or 0% sucrose the subcultured plants continuously proliferated by multiple shoots and generated large, green-colored plants, while with dilution of those nitrogen components and increase of sucrose to 1.5% the red-color anthocyanin pigmentation spread from the glands or glandular hairs to the entire leaves and the plant sizes and dry weight decreased in inverse proportion to the depth of red color. The anthocyanin pigments of Dionaea muscipula consisted of delphinidin 3-0-glucoside which was new to the species and cyanidin 3-0-glucoside (chrysanthemin), and those of Drosera spathulata, studied here for the first time, consisted of cyanidin 3,5-di-0-glucoside (cyanin), cyanidin 3-0-galactoside (idaein), cyanidin 3-0-glucoside, pelargonidin 3-0-galactoside, and pelargonidin 3-0-glucoside (callistephin).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.