Mutants tomato plant

Recent work by Taylor and his colleagues [7], has identified a compound present in ABA-less mutant tomato plants as 2,4-octadienedioic acid (ODA) and suggested that it is the Cjo central residue of a C40 carotenoid from which two C15 (ABA precursor) residues have been removed. When the same H20 experiment was carried out with normal tomato plants, which were then wilted severely, the ABA became labelled with up to 11 deuterium atoms but the ODA was unlabelled except that 20% of the molecules contained just one deuterium atom. This is compatible with the ODA s being formed from an unlabelled carotenoid during the course of the experiment and one of the three doublebonds being saturated by NAD H H"(Fig. 7). 

L6pez-Juez, E. et al.. Response of Hght-grown wild-type and awrea-mutant tomato plants to end-of-day far-red Hght, /. Photochem. Photobiol. B, 4, 391, 1990. 

Kerckhoffs, L.H.J., Sengers, M.M.T., and Kendrick, R.E., Growth analysis of wild-type and photo-morphogenetic-mutant tomato plants, Physiologia Plantarum, 99, 309, 1997. 

RONEN G, COHEN M, ZAMIR D and HIRSCHBERG J (1999) Regnlation of carotenoid biosynthesis during tomato fruit development expression of the gene for lycopene epsilon cyclase is down regulated during ripening and is elevated in the mutant delta . Plant J, 17, 341-51. 

Kausch KD, Handa AK. Molecular cloning of a ripening-specific lipoxygenase and its expression during wild-type and mutant tomato fruit development. Plant Physiol 1997 113 1041-1050. 

Puri, J. Tal, M. Abnormal stomatal behavior and hormonal imbalance In flacca, wilty mutant of tomato. Plant Physiol., 1977, 59, 173-177. 

As described above, desiccation stimulates ABA synthesis and there are high concentrations of ABA in water-stressed leaves. This relation leads to the proposal that ABA mediates the response to drought. Indeed, most ABA deficient mutants display an excessive water loss due to defects in stomatal regulation which leads to an increased tendency to wilt [28,44,99]. Characterization of ABA deficient tomato plants showed a direct relationship between stomatal closure and ABA. The stomata of these plants were unresponsive to water stress but could be closed by applying ABA. ABA synthesized in water-stressed roots may act as a chemical signal to induce stomatal closure before any desiccation of the leaves. When the roots are submitted to stress they will produce ABA that is transported to the aerial parts of the plant and induces stomatal closure to prevent evaporation. This eould be a meehanism to optimize the plant s water use under restricted availability [19]. 

Thus, ODA cannot be formed from the same molecules as ABA it cannot be a by-product of ABA biosynthesis. ODA may be formed from carotenoids in response to stress caused by severe wilting in normal tomato plants and the stress of semi-permanent wilting condition of some tomato mutants [14]. 

Kendrick RE, Kerckhoffs LFU, VanTuinen A, Koornneef M (1997) Photomorphogenic mutants of tomato. Plant Cell Environ 20 746-751... 

Tal M, Imber D, Itai C (1970) Abnormal stomatal behaviour and hormonal imbalance in flacca, a wilty mutant of tomato. Plant Physiol 46 367-373 Tepper HB, Brossard D (1969) Voie de transport de I acide indolylacetique chez Zea et chez le Coleus. CR Acad Sci Paris Ser D 269 567-569 Thimann KV (1972) The natural plant hormones. In Steward FC (ed) Plant physiology. A treatise Vol VIB physiology of development the hormones. Academic Press, London New York... 

Van Tuinen, A., de Vos, C.H.R., Hall, R.D., Plas, L.H.W., van der Bowler, Ch. Bino, R.J. (2006). Use of metabolomics for identification of tomato genotypes with enhanced nutritional value derived from natural light-hyperresponsive mutants. In Plant Genetic Engineering. Volume 7 Metabolic Engineering and Molecular Farming (ed. P.W. Jaiwal), pp. 339-356. Studiinn Press, Houston. 

Hobson G E, Richardson C, Gillham D J 1983 Release of protein from normal and mutant tomato cell walls. Plant Physiol 71 635-638... 

Lazarova, G.l. et al. Molecular analysis of PHYA in wild-type and phytochrome A-deficient mutant of tomato. Plant 14, 653, 1998. 

Lazarova, G.l. et al. Characterization of tomato PHYBl and identification of molecular defects in four mutant alleles. Plant Mol. Biol, 38,1137, 1998. 

Sharma, R. et al.. Identification of photo-inactive phytochrome A in etiolated seedlings and photoactive phytochrome B in green leaves of the aurea mutant of tomato. Plant ]., 4, 1035,1993. 

Bertram, L. and Lercari, B., Kinetics of stem elongation in light grown tomato plants. Responses to different photosynthetically active radiation levels by wild type and aurea mutant tomato,... 

Bradford, K.J., Sharkey, T.D. Farquhar, G.D. (1983). Gas exchange, stomatal behaviour, and 6 C values of the acca tomato mutant in relation to abscisic acid. Plant Physiology, 72, 245-50. 

Emmanuel, E. and Levy, A.A., Tomato mutants as tools for functional genomics. Cum Opin. Plant Biol. 5, 112, 2002. 

Fray, R.G. and Grierson, D., Identification and genetic analysis of normal and mutant phytoene synthase genes of tomato by sequencing, complementation and co-suppression, Plant Mol. Biol. 22, 589, 1993. 

In the absence of suitable cell wall mutants, DCB-adapted tomato cells provide an opportunity to characterise the pectin network of the plant cell wall. It should be noted that synthesis and secretion of hemicellulose is not inhibited but, in the absence of a cellulose framework for it to stick to, most of the xyloglucan secreted remains in soluble form in the cells culture medium (9, 10) while other non-cellulosic polysaccharides and other uronic-acid-rich polymers predominate in the wall. 

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