The LATERAL ORGAN BOUNDARIES Domain gene family in grapevine: Genome-wide characterization and expression analyses during developmental processes and stress responses

LATERAL ORGAN BOUNDARIES (LOB) DOMAIN (LBD) constitute a family of plant-specific transcription factors with key roles in the regulation of plant organ development, pollen development, plant regeneration, pathogen response, and anthocyanin and nitrogen metabolisms. However, the role of LBDs in fruit ripening and in grapevine (Vitis vinifera L.) development and stress responses is poorly documented. By performing a model curation of LBDs in the latest genome annotation 50 genes were identified. Phylogenetic analysis showed that LBD genes can be grouped into two classes mapping on 16 out of the 19 V. vinifera chromosomes. New gene subclasses were identified that have not been characterized in other species. Segmental and tandem duplications contributed significantly to the expansion and evolution of the LBD gene family in grapevine as noticed for other species. The analysis of cis-regulatory elements and transcription factor binding sites in the VviLBD promoter regions suggests the involvement of several hormones in the regulation of LBDs expression. Expression profiling suggest the involvement of LBD transcription factors in grapevine development, berry ripening and stress responses. Altogether this study provides valuable information and robust candidate genes for future functional analysis aiming to clarify mechanisms responsible for the onset of fruit ripening and fruit defense strategies. © 2017 The Author(s)

Mutations causing defects in the biosynthesis and response to gibberellins, abscisic acid and phytochrome B do not inhibit vernalization in Arabidopsis fca-1

The roles of gibberellins, abscisic acid and phytochrome B in the vernalization response were investigated by combining mutations causing defects in their biosynthesis and response with the Arabidopsis thaliana (L.) Heynh. fca-1 mutation. The fca-1 mutation confers a very late-flowering phenotype which can be reversed to wild-type flowering if the seedlings are vernalized. Vernalization was unaffected in gal-3, gai, abi1-1, abi2-1, abi3-1 and phyB-1 backgrounds, suggesting that gibberellin action mediated via GA1 and GAI, abscisic acid action mediated through ABI1 and ABI2, and phytochrome B, function independently of vernalization. However, the mutations did interact with. fca-1 to change flowering time in the absence of vernalization. The abi1 fca-1 and abi2 fca-1 double mutants flowered earlier than fca-1 implying a role for abscisic acid in floral repression. Combination of ga1-3 or gai with fca-1 unexpectedly resulted in opposite interactions, with gai partially suppressing the late flowering of fca-1

Cioutat : a somatic variant of Chasselas exhibiting a programmed cell death-like phenotype

International audienc

Characterization of genetic variation within table grape varieties (Vitis vinifera L.) based on AFLP markers

AFLPs were used to characterize a collection of 35 table grape varieties. A single AFLP reaction with a single combination of selective primers yielded an average of 50 polymorphic and scorable amplified bands in this collection and was enough to unequivocally identify each analyzed variety. Genetic similarity between different varieties was estimated, based on the results obtained with two primer combinations, to be between 0.65 and 0.90, while sibling varieties derived from the same cross showed a genetic similarity higher than 0.80. The analysis of several samples belonging to the same varieties, yet from different origins, showed stability of the AFLP patterns as to unequivocally and reproducibly identify them. Furthermore, some specific primer combinations detected a low level of variation that could be due to somatic variation and would be useful in clonal identification

Genetic relationships among biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) based on AFLP analysis

Genetic similarities between 13 samples belonging to nine reference biotypes and two field populations of Bemisia tabaci (Gennadius), one field population of B. medinae Gomez-Menor and another of B. afer Priesner and Hosny, were evaluated using amplified fragment length polymorphism (AFLP) markers. The results indicate that B. tabaci biotypes can be grouped together with a minimum similarity coefficient of 0.32 and separated from the two other species with a similarity coefficient of 0.07. Bemisia tabaci biotypes were grouped in four clusters which comprised: (i) Near East and Indian subcontinent biotypes; (ii) B and Q biotypes plus a Nigerian population from cowpea; (iii) New World A biotype; and (iv) S biotype and a Nigerian population from cassava. These results were consistent with a previous grouping of biotypes based on RAPD-PCR analysis. The AFLP assay allowed the scoring of a total of 354 polymorphic bands in two reaction events with the use of two primer combinations

Composition and biological activity of the Algerian plant Rosa canina L. by HPLC-UV-MS

The present study was carried out in order to identify and characterize the compounds of Rosa canina fruits by HPLC-UV-MS. The total phenolic determiner by a new Fast Blue method (FBBB), which detects phenolic directly, reported an average total phenolic concentration of 1.7 folds greater than Folin-Ciocalteu (F-C), which indicates that an indirect detection method of total phenolic should be replaced in future studies by the FBBB method. TPC of the ethanolic extract was positively correlated with 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging effect. The DPPH activity of R. canina extract which is higher than the IC50 of the ascorbic acid and Butylated Hydroxytoluene (BHT), but lower than the IC50 of quercetin and trolox. The determination of intracellular reactive oxygen species (ROS) proved the antioxidant effect of the extract on HepG2 and SH-SY5Y cells. A concentration of 1.63g/ml on HepG2 cells had an oxidizing effect instead of the antioxidant effect, which is due to the existence of a tert-butyl group in sesquiterpene identified by HPLC-UV-MS method. These results indicate that the fruits of R. canina can be used as a natural source of antioxidants against oxidative stress and some types of cancer. © 2017 King Saud University