The aconitate hydratase family from Citrus

Terol, Javier; Soler, Guillermo; Talon, Manuel; Cercos, Manuel
January 2010
BMC Plant Biology;2010, Vol. 10, p222
Academic Journal
Background: Research on citrus fruit ripening has received considerable attention because of the importance of citrus fruits for the human diet. Organic acids are among the main determinants of taste and organoleptic quality of fruits and hence the control of fruit acidity loss has a strong economical relevance. In citrus, organic acids accumulate in the juice sac cells of developing fruits and are catabolized thereafter during ripening. Aconitase, that transforms citrate to isocitrate, is the first step of citric acid catabolism and a major component of the citrate utilization machinery. In this work, the citrus aconitase gene family was first characterized and a phylogenetic analysis was then carried out in order to understand the evolutionary history of this family in plants. Gene expression analyses of the citrus aconitase family were subsequently performed in several acidic and acidless genotypes to elucidate their involvement in acid homeostasis. Results: Analysis of 460,000 citrus ESTs, followed by sequencing of complete cDNA clones, identified in citrus 3 transcription units coding for putatively active aconitate hydratase proteins, named as CcAco1, CcAco2 and CcAco3. A phylogenetic study carried on the Aco family in 14 plant species, shows the presence of 5 Aco subfamilies, and that the ancestor of monocot and dicot species shared at least one Aco gene. Real-time RT-PCR expression analyses of the three aconitase citrus genes were performed in pulp tissues along fruit development in acidic and acidless citrus varieties such as mandarins, oranges and lemons. While CcAco3 expression was always low, CcAco1 and CcAco2 genes were generally induced during the rapid phase of fruit growth along with the maximum in acidity and the beginning of the acid reduction. Two exceptions to this general pattern were found: 1) Clemenules mandarin failed inducing CcAco2 although acid levels were rapidly reduced; and 2) the acidless "Sucreña" orange showed unusually high levels of expression of both aconitases, an observation correlating with the acidless phenotype. However, in the acidless "Dulce" lemon aconitase expression was normal suggesting that the acidless trait in this variety is not dependent upon aconitases. Conclusions: Phylogenetic studies showed the occurrence of five different subfamilies of aconitate hydratase in plants and sequence analyses indentified three active genes in citrus. The pattern of expression of two of these genes, CcAco1 and CcAco2, was normally associated with the timing of acid content reduction in most genotypes. Two exceptions to this general observation suggest the occurrence of additional regulatory steps of citrate homeostasis in citrus.


Related Articles

  • Oxidative status and citrate concentration in rat tissues during experimental hyperthyroidism and melatonin treatment. S. Popov; A. Pashkov; T. Popova; V. Zoloedov; A. Semenikhina; T. Rakhmanova // Bulletin of Experimental Biology & Medicine;Aug2007, Vol. 144 Issue 2, p203 

    Abstract  Biochemiluminescence increased, while aconitate hydratase activity and citrate accumulation in tissues of the liver and heart and blood decreased in rats with experimental hyperthyroidism. These changes reflect activation of free radical oxidation, damage to enzyme molecules with...

  • Effect of Succinic Acid and Chitosan Derivatives on Aconitate Hydratase Activity and Citrate Content in Rat Brain Tissues Under Ischemia/Reperfusion Conditions. Safonova, O.; Popova, T.; Slivkin, A.; Belenova, A.; Talmi, Yu. // Pharmaceutical Chemistry Journal;Mar2015, Vol. 48 Issue 12, p771 

    Succinic-acid and chitosan derivatives administered at various dose to rats with brain ischemia/reperfusion led to a decrease in the level of lactate (an ischemia marker) in brain tissue as compared to the value in pathology. The activity of aconitate hydratase (a sensitive target of...

  • malic acid.  // Royal Society of Medicine: Medicines;2002, p346 

    This article presents information on malic acid, a weak organic acid found in apples and some fruits. It is incorporated into some medicinal preparations, such as artificial saliva and skin treatments, to adjust their acidity. It is regarded as safe in normal topical use.

  • Sugar Regulation of Plastid Reversion in Citrus Epicarp is Mediated through Organic Acid Metabolism. Ahmed, Omer Khidir // Pakistan Journal of Biological Sciences;2009, Vol. 12 Issue 3, p246 

    The inhibition by sucrose of chromoplast reversion to chloroplast in citrus epicarp was studied by observing the effects of several sugars, sugar metabolites and 1-iodoacetate on chlorophyll reaccumulation in cultured Citrus' paradisi Macf. pericarp segments. Pericarp segments of 1 cm in...

  • Influence of harvest date and light integral on the development of strawberry flavour compounds. Watson, R.; Wright, C. J.; McBurney, T.; Taylor, A. J.; Linfort, R. S. T. // Journal of Experimental Botany;Oct2002, Vol. 53 Issue 377, p2121 

    Strawberries cv. Elsanta were grown in peat bags in a glasshouse and subjected to three shading levels (0%, 25%, 47%) for 2 weeks, commencing 1 week prior to first fruit ripening. Fruit was harvested at five intervals and analysed using Atmospheric Pressure Chemical Ionization (APCI) and direct...

  • Effects of Preharvest Bagging on Quality of Black Table Grapes. Signes, Antonio J.; Burlo, Francisco; Martínez-Sánchez, Francisco; Carbonell-Barrachina, Ángel A. // World Journal of Agricultural Sciences;Jan2007, Vol. 3 Issue 1, p32 

    The effects of bagging grapes bunches from a black variety of table grapes (Perla) with cellulose bags on their chemical and sensory properties were studied. This pre-harvest technique, bagging, provided a more uniform color of Perla grapes than non-bagged samples (lower values of the standard...

  • Comparative Study of Sugars, Organic Acids and trans-Resveratrol in Red and White Grapes Grown in Denizli Region, Turkey. OTAG, M.; KADAKAL, Ç. // Asian Journal of Chemistry;2015, Vol. 27 Issue 8, p3121 

    Grape berry ripening includes a broad range of physical and biochemical processes. In this study, compare the changes in organic acid, sugar and trans-resveratrol content during at four different ripening stages (lag phase, veraison, maturity and late harvest) between red (Çalkarasi and...

  • A DIGE-based quantitative proteomic analysis of grape berry flesh development and ripening reveals key events in sugar and organic acid metabolism. Martínez-Esteso, Maria José; Sellés-Marchart, Susana; Lijavetzky, Diego; Pedreño, Maria Angeles; Bru-Martínez, Roque // Journal of Experimental Botany;May2011, Vol. 62 Issue 8, p2521 

    Grapevine (Vitis vinifera L.) is an economically important fruit crop. Quality-determining grape components, such as sugars, acids, flavours, anthocyanins, tannins, etc., are accumulated during the different grape berry development stages. Thus, correlating the proteomic profiles with the...

  • Growth of Campylobacter in Media Supplemented with Organic Acids. Hinton Jr., Arthur // Journal of Food Protection;Jan2006, Vol. 69 Issue 1, p34 

    The growth of Campylobacter spp. in media supplemented with organic acids was examined. A Bioscreen C Microbiology Reader was used to measure growth of cultures incubated at 37°C for 48 h in a tryptose-yeast extract basal broth medium and in basal broth supplemented with 10, 20, 30, 40, or 50...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics