Ethylene signal transduction elements involved in chilling injury in non-climacteric loquat fruit

Loquat (Eriobotrya japonica Lindl.) is a subtropical fruit, with some cultivars such as ‘Luoyangqing’ (LYQ) susceptible to chilling injury (CI), while others such as ‘Baisha’ (BS) are resistant. Although loquats are non-climacteric, modulation of ethylene has an effect on ripening-related post-harvest CI. Therefore the role of ethylene signalling in the development of CI was investigated in fruit of both the LYQ and BS cultivars. Three ethylene receptor genes, one CTR1-like gene, and one EIN3-like gene were isolated and characterized in ripening fruit. All of these genes were expressed differentially within and between fruit of the two cultivars. Transcripts either declined over fruit development (EjERS1a in both cultivars and EjEIL1 in LYQ) or showed an increase in the middle stages of fruit development before declining (EjETR1, EjERS1b, and EjCTR1 in both cultivars and EjEIL1 in BS). The main cultivar differences were in levels rather than in patterns of expression during post-harvest storage. EjETR1, EjCTR1, and EjEIL1 genes showed increased expression in response to low temperature and this was particularly notable for EjETR1, and EjEIL1 during CI development in LYQ fruit. The genes were also differentially responsive to ethylene treatment, 1-methycyclopropene (1-MCP) and low temperature conditioning, confirming a role for ethylene in regulation of CI in loquat fruit

Molecular cloning and nucleotide sequence of a metallothionein-like protein from apricot fruit (Accession nø U97494). Gene expression during fruit ripening

url=http://www.tarweed.com/pgr/PGR97-160.htmlInternational audienc

Molecular cloning and nucleotide sequence of a Rab 7 small GTP-binding protein from apricot fruit (Accession nø U82219). Gene expression during fruit ripening

url=http://www.tarweed.com/pgr/PGR97-117.htmlInternational audienc

Sequence of an O-methyltransferase from apricot fruit (Accession nø U82011). Gene expression during fruit ripening

url=http://www.tarweed.com/pgr/PGR97-118.htmlInternational audienc

Antioxidant activity of tropical fruits as related to their polyphenol, vitamin C and carotenoid contents: a review

National audienceToday's consumers are more and more concerned with foods containing components that are providing health benefit, such as polyphenols, vitamins and carotenoids. The contribution of these components to health benefit in plant-derived food has often been related to their antioxidant properties. Most studies on these components in fruits have been carried out in temperate countries. Less is known about them in fruits from tropical areas, whereas the international trading of tropical fruits is developing. This paper summarizes knowledge on polyphenols, vitamin C and carotenoids in tropical fruits in relation to their measured antioxidant activity. Data on the composition of these fruits in vitamins have been recently published. Less information is available on their total phenolic content and their phenolic composition. A statistical analysis including data on various tropical fruits has shown that the correlation coefficient between antioxidant activity and total phenolic content was 0.96. The corresponding coefficient for ascorbic acid amounted 0.23 to 0.35, depending on the method used to measure the antioxidant activity. It is noticeable that in acerola (Malpighia emarginata) and guava (Psidium guajava), which exhibit the highest antioxidant activity, this activity is highly linked to both total phenolic and ascorbic acid contents. Antioxidant activity was shown to be negatively correlated to carotenoid content in guava. However, it is generally not clear which compounds are responsible for the antioxidant properties of tropical fruits, as they have rarely been simultaneously analyzed for their composition in all these components and their antioxidant activity. Moreover, total phenolic, ascorbic acid and carotenoid contents may be highly influenced by cultivars, as suggested in mango and guava pulp. The effects of the development and maturation stages and of postharvest storage conditions on these components and on antioxidant activity in tropical fruits still need to be investigated

Molecular cloning and nucleotide sequence of an abscisic acid-, stress-, ripening-induced (ASR) -like protein from apricot fruit (Accession nø U93164). Gene expression during fruit ripening

url=http://www.tarweed.com/pgr/PGR97-166.htmlInternational audienc

Sequence of AFTP1, a cysteine proteinase from apricot fruit (Accession nø U93166). Gene expression during fruit ripening

url=http://www.tarweed.com/pgr/PGR97-179.htmlInternational audienc

Expression of MADS genes in harvested banana fruit in relation to finger drop

Banana finger drop is a dislodgement of individual fruits from the hand at the pedicel area. Recent findings led us to suggest developmental cues as additional factors, beside ethylene, acting to control the finger drop process. Assuming that this developmental control involved MADS-box components as shown in other fruit, we analyzed here the MADS-box gene expression in the median (control zone, CZ) and pedicel rupture (drop zone, DZ) areas of the peel tissue from banana harvested at different physiological stages. In immature fruits, the mRNA level of MaMADS1, MaMADS2 and MaMADS6 genes were transitorily enhanced in DZ as compared to control. In early mature green fruit, MaMADS2 and MaMADS5 mRNA were highly and transitorily induced in the DZ, with a peak observed at day 2, as compared to the CZ. MaMADS2, MaMADS3 and MaMADS4 mRNA accumulated at comparable levels in both zones. In late mature green fruit, all MaMADS genes were transiently and differentially induced according to the peel zone, except MaMADS6 that increased slightly without any marked change in CZ and DZ. The MaMADS3 mRNA level was comparable in both zones while that of MaMDAS4 was enhanced in DZ. In banana fruit, MaMADS box genes may participate in this sequence of events with MaMADS2 and MaMADS4, and to a lesser extent MaMADS5, being associated with finger drop. They act sequentially to control the process, with MaMADS2 and MaMADS5 beginning earlier and MaMADS4 acting later. Findings offer insights regarding upstream regulatory factors and roles of MADS genes associated with finger drop. For improving banana quality traits, comparative analysis of MADS box genes expression enables selecting candidate genes for molecular marker identification. Next steps may (i) identify related molecular marker(s) and (ii) validate these markers via genetic association studies on a segregating population