Characterization of the major fragance gene from an aromatic japonica rice and analysis of its diversity in Asian cultivated rice

In Asian cultivated rice (Oryza sativa L.), aroma is one of the most valuable traits in grain quality and 2-ACP is the main volatile compound contributing to the characteristic popcorn-like odour of aromatic rices. Although the major locus for grain fragrance (frg gene) has been described recently in Basmati rice, this gene has not been characterised in true japonica varieties and molecular information available on the genetic diversity and evolutionary origin of this gene among the different varieties is still limited. Here we report on characterisation of the frg gene in the Azucena variety, one of the few aromatic japonica cultivars. We used a RIL population from a cross between Azucena and IR64, a non-aromatic indica, the reference genomic sequence of Nipponbare (japonica) and 93–11 (indica) as well as an Azucena BAC library, to identify the major fragance gene in Azucena. We thus identified a betaine aldehyde dehydrogenase gene, badh2, as the candidate locus responsible for aroma, which presented exactly the same mutation as that identified in Basmati and Jasmine-like rices. Comparative genomic analyses showed very high sequence conservation between Azucena and Nipponbare BADH2, and a MITE was identified in the promotor region of the BADH2 allele in 93–11. The badh2 mutation and MITE were surveyed in a representative rice collection, including traditional aromatic and non-aromatic rice varieties, and strongly suggested a monophylogenetic origin of this badh2 mutation in Asian cultivated rices. Altogether these new data are discussed here in the light of current hypotheses on the origin of rice genetic diversity

Proteolyse et texture des fromages a pate cuite pressee . I . Influence de l'activite de l'eau

37 ref.National audienc

Responses of cultured tobacco cells to cryptogein, a proteic elicitor from Phytophthora cryptogea

National audienc

Responses of cultured tobacco cells to cryptogein, a proteic elicitor from Phytophthora cryptogea

National audienc

Characterization, functional validation and gene expression patterns of two 14-3-3 isoforms from Vitis vinifera

In eukaryotic cells, 14-3-3 proteins constitute a family of conserved regulatory proteins which bind to a large number of phosphorylated partners. Although a great body of evidences accumulated in herbaceous species indicates that 14-3-3s play key roles in regulation of plant growth, information about function in tree plants is still very scarce. In this paper, we report the characterization of two novel 14-3-3s from grapevine (Vitis vinifera 'Cabernet Sauvignon') named VV1_CS and VV2_CS. The VV1_CS and VV2_CS cDNA were expressed in Escherichia coli and the recombinant proteins were shown to be functional proteins using plasma membrane H+-ATPase as target. Transcript analysis during grape development or under elicitor-induced stress revealed differential expression of the two 14-3-3 isoforms

The gene for fragrance in rice

The flavour or fragrance of basmati and jasmine rice is associated with the presence of 2-acetyl-1-pyrroline. A recessive gene (fgr) on chromosome 8 of rice has been linked to this important trait. Here, we show that a gene with homology to the gene that encodes betaine aldehyde dehydrogenase (BAD) has significant polymorphisms in the coding region of fragrant genotypes relative to non-fragrant genotypes. The accumulation of 2-acetyl-1-pyrroline in fragrant rice genotypes may be explained by the presence of mutations resulting in a loss of function of the fgr gene product. The allele in fragrant genotypes has a mutation introducing a stop codon upstream of key amino acid sequences conserved in other BADs. The fgr gene corresponds to the gene encoding BAD2 in rice, while BAD1 is encoded by a gene on chromosome 4. BAD has been linked to stress tolerance in plants. However, the apparent loss of function of BAD2 does not seem to limit the growth of fragrant rice genotypes. Fragrance in domesticated rice has apparently originated from a common ancestor and may have evolved in a genetically isolated population, or may be the outcome of a separate domestication event. This is an example of effective human selection for a recessive trait during domestication