Lorenzo Guglielminetti

Publications (7)13.49 Total impact

• Article: Amylolytic activity and carbohydrate levels in relation to coleoptile anoxic elongation in Oryza sativa genotypes.

  Antonio Pompeiano, Francesca Fanucchi, Lorenzo Guglielminetti
  [show abstract] [hide abstract]
  ABSTRACT: Among starchy seeds, rice has the unique capacity to germinate successfully under complete anaerobiosis. In this conditions, starch degradation is supported by a complete set of starch-degrading enzymes that are absent or inactive in cereals except rice. A characterization of carbohydrate metabolism and starch-degrading enzyme activity across twenty-nine genotypes of Oryza sativa L. is presented here. The zymogram of amylolytic activities present in rice embryos and endosperms under anaerobic conditions seven days after sowing (DAS) revealed marked differences among cultivars. Coleoptile elongation was positively correlated with total amylolytic activities and α-amylase activity in embryos, and negatively correlated with α-amylase activity in endosperm. Moreover, carbohydrate content in embryos was found to be positively correlated with total amylolytic activities under anaerobic conditions, while a negative relationship was recorded in the endosperm. Carbohydrate status in rice seedlings has a primary importance in sustaining coleoptile elongation towards the surface. The relationship between carbohydrate level in embryo and anoxic germination, as well as with total amylolytic activities present in rice embryo under anaerobic condition 7 DAS, is consistent with the role of sugar metabolism to support rice germination under oxygen-deprived environment.
  Journal of Plant Research 06/2013; · 1.75 Impact Factor
• Source

  Available from: Pierdomenico Perata

  Article: Carbohydrate–ethanol transition in cereal grains under anoxia

  Lorenzo Guglielminetti, Héctor Abel Busilacchi, Pierdomenico Perata, Amedeo Alpi
  New Phytologist 12/2001; 151(3):607 - 612. · 6.64 Impact Factor
• Article: Effect of Anoxia on α -Amylase Induction in Maize Caryopsis

  Lorenzo Guglielminetti, Héctor Abel Busilacchi, Amedeo Alpi
  [show abstract] [hide abstract]
  ABSTRACT: -amylase as well as other enzymes involved in starch degradation under anoxia. Carbohydrates resulting from starch breakdown allow maize caryopses to avoid sugar starvation. Most interestingly, this correlates well with the ability of maize caryopses to sustain relatively prolonged anaerobiosis, in agreement with the hypothesis linking carbohydrate availability to anoxia tolerance.
  Journal of Plant Research 05/2000; 113(2):185-192. · 1.75 Impact Factor
• Source

  Available from: Pierdomenico Perata

  Article: Sucrose Synthesis in Cereal Grains under Oxygen Deprivation

  Lorenzo Guglielminetti, Elena Loreti, Pierdomenico Perata, Amedeo Alpi
  Journal of Plant Research 08/1999; 112(3):353-359. · 1.75 Impact Factor
• Article: Gibberellins in suspensor, embryo and integument from very young seeds of Phaseolus coccineus L.

  Piero Picciarelli, Alberto Piaggesi, Nello Ceccarelli, Lorenzo Guglielminetti, Amedeo Alpi
  [show abstract] [hide abstract]
  ABSTRACT: Endogenous gibberellins (GAs) were extracted from suspensor, embryo and integument of very young seeds of Phaseolus coccineus L. and detected by combined gas chromatography-mass spectrometry (GC-MS). Results show the presence of one C20-GA, GA44 and five C19-GAs in the suspensor: GA1, GA4, GA5, GA6 and GA8, and four C19-GAs in the integument: GA1, GA5, GA6 and GA8. Only traces of GA1 and GA5 were identified in the embryo. A compound structurally related to GAs was identified as tetrahydroxy-Kauranoic acid in suspensor, integument and, only in trace amounts, in the embryo.
  Plant Growth Regulation 02/1994; 14(2):183-185. · 1.60 Impact Factor
• Article: Characterization of isoforms of hexose kinases in rice embryo

  Lorenzo Guglielminetti, Pierdomenico Perata, Akiyoshi Morita, Elena Loreti, Junji Yamaguchi, Amedeo Alpi
  [show abstract] [hide abstract]
  ABSTRACT: Hexose kinases in rice embryos have been characterized. Six isoforms were detected: i.e. three glucokinases (GK1–3), two hexokinases (HK1 and HK2) and one fructokinase (FK1). Out of these, GK3, HK1 and HK2 were inhibited by mannoheptulose and glucosamine, known inhibitors of hexokinase activity. These inhibitors are also known to be modulators of sugar sensing processes. The results suggest that GK3, HK1 and HK2 may play a role in sensing the cellular sugar status in the rice embryo.
  Phytochemistry.
• Article: Anaerobic carbohydrate metabolism in wheat and barley, two anoxia-intolerant cereal seeds

  Pierdomenico Perata, Lorenzo Guglielminetti, Amedeo Alpi
  [show abstract] [hide abstract]
  ABSTRACT: Cereals such as barley and wheat are unable to germinate under anoxic conditions. Data are presented on the utilization of the soluble sugars present in the dry seed of wheat and barley kept under strict anoxia, together with the status of the enzymes involved in the metabolism of carbohydrates. The amount of glucose, fructose, and sucrose decreases during the anaerobic treatment, indicating that carbohydrate metabolism takes place in the seeds of wheat and barley kept under anoxic conditions. The analysis of the enzymes involved in the metabolism of carbohydrates shows that the enzymatic set needed to convert sucrose, glucose, and fructose to glucose-6P is present in the anaerobic seeds. Sucrose degradation seemingly occurs through a sucrose synthase pathway with nucleoside diphosphate kinase involved in the cycling of urydilates. However, the activity of sucrose synthase, glucokinase, and fructokinase, all strongly induced in rice, an anoxia-tolerant cereal, are almost unaffected or even depressed in the two cereal seeds under investigation. The comparison of the results obtained and described in this paper with the published data on the metabolism of carbohydrates in rice, indicate that the anoxia-intolerant species would rapidly suffer and eventually die from sugar starvation if kept under anoxia for a relatively prolonged length of time (4–8 d).