ITEMS FROM ITALY

EXPERIMENTA INSTITUTE FOR CEREAL RESEARCH

Via Cassia 176, 00191, Rome, Italy.

Toxicity testing of alcohol-soluble proteins from Triticum monococcum in coeliac disease.

N.E. Pogna, C. Saponaro, M. De Vincenzi, R. Luchetti, and M.R. Dessi.

Alcohol-soluble proteins from the flours of five accessions of T. monococcum were submitted to a peptic-tryptic (PT) sequential digestion and fractionated by affinity chromatography onto a column containing Sepharose 6-B coupled with mannan. The loaded peptides eluted in three fractions. Fraction C peptides were shown to agglutinate myelogenous leukemia K562S cells, and agglutination was correlated strongly with toxicity in coeliac disease. On the contrary, fractions A and B and the unfractionated PT-digests were not active, even at a concentration as high as 10 g/l (see Table 1). When added to active peptides in fraction C, peptides in fraction B were able to inhibit cell agglutination. Results suggest that whole PT-digests from the T. monococcum accessions are not able to agglutinate the K562S cells, because peptides in fraction B interfere with agglutinating properties in fraction C. The same inhibition mechanism is assumed to account for the low toxicity, if any, of monococcum proteins in coeliac disease as determined by in vitro tests based on cultured coeliac jejunal mucosa and fetal rat intestine (Auricchio et al. 1982, Pediatr Res 16:1004).

Spontaneous mutants of T. monococcum lacking certain storage proteins are being investigated currently to identify the `protective' peptides in fraction B and the active components in fraction C.

Table 1. Agglutinating activity of PT-digests from five Triticum monococcum

accessions against K562S cells.

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Agglutinating activity1

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Accession Whole Fraction Fraction Fraction Fraction

No. PT-digest A B C B + C2

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362 ó ó ó 65 ó

363 ó ó ó 18 ó

1331 ó ó ó 72 ó

1378 ó ó ó 21 ó

1382 ó ó ó 42 ó

Control Bread wheat

cv.S.Pastore 73 nt nt nt nt

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1Minimal peptide concentration (mg/l) required to agglutinate 100 % of cells.

2The concentration of peptides in fraction C is indicated in the fourth column, that

of peptides in fraction B is 10g/l.

ó = negative even at a concentration of 10g/l; nt = not tested.

Reaction of durum wheat cultivars to black point disease.

M. Pasquini, S. Pagliaricci, L. Sereni, F. Casini, M. Mazza, and N. Pogna.

Black point is a serious problem in durum wheat in Italy, in areas receiving heavy rainfall during the early stages of seed development. A study determined the fungi present on kernels of the Italian durum wheat cultivars Creso, Simeto, Tavoliere, and Ofanto, grown in 10 sq m plots with three replications, in a wheat-growing area of central Italy.

The percentage of the fungal isolates of each species on the total number of isolations was calculated at the dough stage on 18 heads per plot. After harvesting, black-point incidence and intensity were determined based on the percentage of black-pointed kernels in a 500 kernel sample. Mycological analyses were carried out on the affected seeds. Sampling and classification were according to Rossi et al. (1991) and Huguelet and Kiesling (1973).

Alternaria spp. were the prevalent fungi isolated from kernels, before and after harvesting, whereas a low percentage of seed was infected by Drechslera sorokiniana. The cultivar Simeto was shown to be the least affected genotype (black-point incidence = 4.4 %; intensity = 1.0 %), whereas Tavoliere and Ofanto were the most susceptible (disease incidence = 67.4 and 80.5 % respectively; intensity = 1.7 and 1.9 % respectively). However, according to previous observations, the behavior of the cultivars was variable through the years and regions.

A relationship was discovered between frequency of Alternaria spp. during seed development and the incidence and intensity of kernel discoloration. Simeto had a low frequency of isolation of Alternaria at the dough stage (36.3 % of kernels), and the lowest proportion of black-pointed kernels. However, Tavoliere and Ofanto were consistently high in black point, and Alternaria was isolated with the highest frequency during seed development (46.5 and 57.8 % of kernels, respectively). At harvest, Alternaria was isolated at a high frequency from the black-pointed seeds of the four cultivars, whereas D. sorokiniana occurred only in the cultivar Creso (15 % of kernels).

Artificial inoculation methods are being developed to test the cultivars and to study the inheritance of resistance to black point.

References.

Huguelet JE and Kiesling RL 1973. Influence of inoculum composition on the black point disease of durum wheat. Phytopath 63:1220-1225.

Rossi V, Manici LM, and Frisullo S. 1991. Indagine sulla micoflora delle spighe di frumento duro, in rapporto alla volpatura delle cariossidi. Petria 1:37-50.

Transfer of resistance to fungal diseases from rye into durum wheat.

M. Pasquini, N.E. Pogna, M. Mazza, S. Pagliaricci, and P. Cacciatori.

Tetraploid wheat lines carrying the 1BL·1RS translocation were found to have resistance to some foliar diseases (leaf rust, stem rust, yellow rust, and powdery mildew) and poor gluten quality, the latter character probably because of the secalins encoded by the Sec-1 locus. In order to break the linkage between the resistance genes Lr26, Sr31, and Yr9 and the Sec-1 locus through allosyndetic recombination between 1RS and its wheat homoeologue 1BS, these tetraploid wheat lines were crossed with the ph1c mutant of the durum wheat cultivar Cappelli.

The F2 progeny from these crosses were inoculated artificially with the Pr12 leaf rust isolate, avirulent to Lr26. The seedlings resistant to this isolate were analyzed by Southern blotting using the PSR128 probe to identify genotypes homozygous for ph1c. A-PAGE and SDS-PAGE analysis on the seeds from plants resistant to leaf rust and homozygous for ph1c identified the presence of the secalins encoded by the Sec-1 locus and prolamins encoded by the Gli-B1 and Glu-B3 loci. The corresponding F3 plants were screened for reaction to the Pr12 isolate. Among the 128 progeny, six putative allosyndetic recombinants resistant to leaf rust, but lacking secalins, were isolated. These recombinants were shown to contain the Gli-B1 and Glu-B3-encoded prolamins.

Publications.

Pogna NE, Redaelli R, Vaccino P, Peruffo ADB, Curioni A, Metakovsky EV, and Pagliaricci S. 1995. Production and genetic characterization of near-isogenic lines in the bread wheat cultivar Alpe. Theor Appl Genet 90:650-658.

Redaelli R, Morel M-H, Autran J-C, and Pogna NE. 1995. Genetic analysis of low Mr glutenin subunits fractionated by two-dimensional electrophoresis A-PAGE x SDS-PAGE. J Cereal Sci 21:5-13.

Redaelli R, Morel M-H, Autran J-C, and Pogna NE. 1995. Two-dimensional (A-PAGE x SDS-PAGE) electrophoresis of Glu-A3 alleles in some cultivars carrying different Gli-A-1 alleles. In: Wheat Kernel Proteins. Molecular and Functional Aspects, University of Viterbo. Pp. 115-120.

Popineau Y, Pogna NE, and Lefebvre J. 1995. Rheological properties of glutens differing by their glutenin subunit compositions. In: Wheat Kernel Proteins. Molecular and Functional Aspects, University of Viterbo. Pp. 129-134.

Boggini G, Tusa P, and Pogna NE. 1995. Protein composition and breadmaking quality of durum wheat. In: Wheat Kernel Proteins. Molecular and Functional Aspects, University of Viterbo. Pp. 291-293.

Peruffo ADB, Curioni A, Furegon L, and Pogna NE. 1995. A 60 Kda protein is a component of medium-sized aggregates. In: Wheat Kernel Proteins. Molecular and Functional Aspects, University of Viterbo. Pp. 345-348.

Boggini G, Tusa P, and Pogna NE. 1995. Breadmaking quality of durum genotypes with unusual glutenin compositions. J Cereal Sci 22:105-113.

Pogna NE, Metakovsky EV, Redaelli R, Dachkevitch T, and Cernakov VM. 1995. The group 1 chromosomes of wheat contain several loci coding for gliadins. Proc 8th Inter Wheat Genet Symp (ZS Li and ZY Xin eds), China Agricultural Scientech Press, Beijing. Pp. 137-140.

Bianchi B, Pogna NE, Borghi B, Zheng DS, and Giorgi B. 1995. The past and the possible future impact of the Italian germplasm in breeding of wheat in China. Proc 8th Inter Wheat Genet Symp (ZS Li and ZY Xin eds), China Agricultural Scientech Press, Beijing. Pp. 1235-1240.

Saponaro C, Pogna NE, Castagna R, Pasquini M, Cacciatori P, and Redaelli R. 1995. Allelic variation at the Glu-A1m, Gli-A1m and Gli-A2m loci and breadmaking quality in Triticum monococcum. Genet Res, Camb 66:127-137.

Autran J-C, Hamer RJ, Plijter JJ, and Pogna NE. 1995. Ameliorer la qualite d' utilization industrielle des bles europeens. Sinthese des resultats du programme CEE ìECLAIRî (1991-1994). Industries des Cereales, Octobre 1995:11-27.

Pogna NE, Pasquini M, Mazza M, Pagliaricci S, Redaelli R, and Vaccino P. 1995. Technological and nutritional quality of wheat: genetic basis and breeding by chromosomal and gene mutation. In: Proc Inter Symp Use of Induced Mutations and Molecular Techniques for Crop Improvement, Vienna 19-23 June 1995, IAEA. Pp. 77-91.

Pasquini M, Sereni L, Casulli F, Siniscalco A, Landini M, Mameli L, Gallo G, Monti M, Lo Re L, Coppolino F, Padovan S, Minoia C, and Jenabzadeh P. 1995. Malattie fungine comparse nei frumenti duri e teneri nall' annata agraria 1994-95. L'Infrom Agrario 35:45-52.