Biochemical and cytological studies of genetic transfer from the Mv genome of Aegilops ventricosa into hexaploid wheat

A double interspecific oross {Triticum turgidum (AB) var. rubroatrum H-l-1 x Ae. ventvicosa (DM°) AP-l} x T.aestivum (ABD) cv. Almatense H-10-1S was carried out in 1950 by M. Alonso Peña (Cuenca, Spain) and 70 Unes were devived from it by vepeated selfing (Unes H-93-1 thvough 70). Pveliminavy biochemical evidence indicated genetic tvansfev fvom the M° genome of Ae.ventvicosa into some of these Unes. A more detailed biochemical and cytological characteriza tion of the H-93- Unes was undertaken. A progress report of these studies is presented here. Fourten biochemical systems, each representing a set of up to 4 homoeologous loci, weve investigated in the vavental material, in the H-93- Unes, and in Ae. squavrosa (DD), Ae. comosa (MM) and Ae. uniaristata (M^-M11). Biochemical markers controlled by the A or B genomes of one or both wheat parents weve distributed in the H-93- Unes as expected if the egcells fvom the self-stevile ABDM0 hybvid, rescued by the ABD polen, cavvied the complete A and B genomes from T. tuvgidum. The distvibution of biochemical mavkevs contvolled by the D genomes of one ov both D genome parents indicated that most of the eggcells from the ABDM0 hybrid carvied most of the D genome, i.e. 3 out of 8 markers of the former tupe were absent in a few Unes each, ind.icating incomplete homology between the two D genomes, non-homologous transfer or deletion. Biochemical characters present in Ae. ventricosa (DM°), Ae. comosa (M), Ae. uniaristata (M11) and absent in T. aestivum (ABD), Ae. squarrosa (D) and T. tuvgidum (AB) were selected as M° genome markers. Two of these markers were not transmited to the H-93- Unes, three were tvansmitted with low fvequency and one with a high fvequency. Resistance to Erisiphe graminis was determined by Dosba and Doussinault at Rennes and was found to be transmitted with low fvequency. Somatic chromosome numbers of the H-93- Unes were counted and all weve found to be hexaploid. Meiosis was studied in Unes cavvying M° genome mavkevs and in their hybrids with the T. aestivum parent, to determine the máximum numbev of alien chvornosornespvesent in each Une. The joint considevation of the biochemical and the cytological evidence se^me to indícate that the genetic tvansfev has taken place by chvomosome substitution and by vecombination

Transfer of resistance to eyespot disease from Aegilops ventricosa to wheat

The extraspecific transfer of genes into cultivated plants is of considerable interest both in basic and applied terms (Sears, 1956; Riley and Kimber 1966). The wild grass Aegilops ventricosa has been recognised for almost 30 years as an important potential donor of genes that determine characters of agronomic interest. More specifically, Sprague (1936) discovered in this species a high level of resistance to the fungus Pseudocercosporella herpotrichoides, which causes eyespot disease. This disease is responsible for considerable lodging and reductions of yield in extensive áreas of wheat cultivation. The level of resistance of wheat cultivars is too low, even among the less susceptible ones (Capelle Desprez and Cerco) and no single genes for resistance had been described in any species. Attemps to transfer resistance from Ae.ventricosa to wheat had been only partially successful. The purpose of this paper is to review work carried out in our laboratory for the past 12 years on the transfer of genes between these two species. This work has led to the recent demonstre^ tion of a major dominant gene for resistance, which confers a high level of resistance to cultivated wheat

Introducción de genes extraespecíficos en el trigo

La introducción de caracteres extragenéricos o extraespecíficos en plan tas cultivadas tiene interés teórico y una reconocida importancia práctica (ver p.ej. ref.1). En el caso de los trigos cultivados, pueden actuar como donadores de genes que controlan caracteres de calidad, de resistencia a agentes patógenos, etc., especies afines de los géneros Sécale, Agropyron y Aegilops. Los métodos empleados para la introducción de estos caracteres son variados y dependen de la afinidad existente entre la especie donadora y la receptora. El proceso de transferencia requiere, en primer lugar, salvar los impe_ dimentos que se presentan para el acceso del material genético extraño al núcleo receptor y, posteriormente, lograr la integración estable de dicho material

Resistance to eyespot (Pseudocercosporella herpotricoides) and distribution of biochemical markers in hexaploid lines derived from double cross (Triticum turgidum x Aegilops ventricosa) x T. aestivum

There are not good intraspecific sources of resistance to the eyespot disea se of wheat, aaused by Cercosporella herpotrichoides Fvon . The -ínterspecifia transfer of genes for resistanoe from Aegitops ventricosa into hexaploid wheat has been only partially achieved, because the degree of resistanoe attained is not as high as that of the donor. We report here on the transfer of resistanoe in a double oross (Triticum turgidum var. rubroatrwv H-1-1 x Ae.ventricosa AP-D x T.aestivum cv. Almatense H-10-15. The high level of resistanoe in a high proportion of the lines strongly suggests a simple genetic control for this oharacter (possibly by one major gene). The gene(s) responsible for resistanoe in the selected lines must be associa ted with the D genome of Aegilops ventricosa on the basis of a detailed study of the distribution of biochemioal markers in the H-93 lines. These results do not exelude that genes with similar effeets might be looated in the M° genome

New dimeric inhibitor of heterologous α-amylases encoded by a duplicated gene in the short arm of chromosome 3B of wheat (Triticum aestivum L.)

A new wheat dimeric α-amylase inhibitor, designated WDAI-3, has been characterized. WDAI-3 is a homodimeric protein active against α-amylase from human saliva and from the insect Tenebrio molitor, but inactive against that from pig pancreas or against trypsin. Its N-terminal amino acid sequence is closer to those of the wheat dimeric inhibitors 0.19 and 0.53 (89–91% identical positions in 44 residues) than to that of the monomeric 0.28 inhibitor (69% identical positions). Iha-BI-2, the gene encoding the new inhibitor, is located in the short arm of chromosome 3B, where it is part of an intrachromosomal gene duplication that also codes for the 0.53 inhibitor

Evolutionary implications of sequential homologies among members of the trypsin/a-amylase inhibitors family (CM-proteins) in wheat and barley

The N-terminal amino acid sequence of four members of the trypsin/α-amylase inhibitor family in wheat, CM1, CM2, CM16 and CM17, has been investigated for 27–29 cycles by automated sequencing procedure. None of the proteins showed inhibitory activity against trypsin or α-amylases from different sources. The N-terminal sequences of these four proteins present a high degree of homology to each other as well as to those reported for other members of the same family in wheat and barley. Such homology is higher between a given protein and a second one associated with a different genome than between that protein and any other encoded in the same genome, indicating that most of the dispersion of the corresponding multi-gene family over several chromosomes took place before the wheat/barley evolutionary branching-ou

Differential in vitro and in vivo effect of barley cysteine and serine protease inhibitors on phytopathogenic microorganisms

Protease inhibitors from plants have been involved in defence mechanisms against pests and pathogens. Phytocystatins and trypsin/α-amylase inhibitors are two of the best characterized protease inhibitor families in plants. In barley, thirteen cystatins (HvCPI-1 to 13) and the BTI-CMe trypsin inhibitor have been previously studied. Their capacity to inhibit pest digestive proteases, and the negative in vivo effect caused by plants expressing these inhibitors on pests support the defence function of these proteins. Barley cystatins are also able to inhibit in vitro fungal growth. However, the antifungal effect of these inhibitors in vivo had not been previously tested. Moreover, their in vitro and in vivo effect on plant pathogenous bacteria is still unknown. In order to obtain new insights on this feature, in vitro assays were made against different bacterial and fungal pathogens of plants using the trypsin inhibitor BTI-CMe and the thirteen barley cystatins. Most barley cystatins and the BTI-CMe inhibitor were able to inhibit mycelial growth but no bacterial growth. Transgenic Arabidopsis plants independently expressing the BTI-CMe inhibitor and the cystatin HvCPI-6 were tested against the same bacterial and fungal pathogens. Neither the HvCPI-6 expressing transgenic plants nor the BTI-CMe ones were more resistant to plant pathogen fungi and bacteria than control Arabidopsis plants. The differences observed between the in vitro and in planta assays against phytopathogenic fungi are discusse

A dimeric inhibitor of insect a-amylase from barley. Cloning of the cDNA and identification of the protein

A cDNA clone, designated pUP-44, whose longest open reading frame codes for a protein that is homologous to the wheat α-amylase inhibitors, has been isolated from a library obtained from developing barley endosperm. The deduced sequence for the mature protein, which is 122 residues long, is preceded by a sequence of 30 residues which has the typical features of a signal peptide. A closely corresponding protein, designated BDAI-1, has been isolated from mature endosperm. BDAI-1 behaves as a dimer and inhibits the α-amylase from the insect Tenebrio molitor at concentrations that have no effect on salivary or pancreatic α-amylases

Inhibition of bacterial and fungal plant pathogens by thionins of types I and II

Thionins are cysteine-rich, 5 kDa polypeptides which are active against plant pathogens. Thionins of type I, from the endosperms of wheat (Wα1, Wα2, Wβ) and barley (Bα, Bβ), and of type II, from barley (BLa, BLb, BLc), have been purified to apparent homogeneity. For a given pathogen, the effective concentration giving 50% inhibition (EC-50) determined for the different thionins varied over a less than fivefold range. The ranking of the variants according to their activity differed among different pathogens, but certain variants, such as Wα1, Wβ or Bβ, tended to be more active than the others. Strains of some bacterial species, such as Clavibacter michiganensis subsp. sepedonicus or Pseudomonas solanacearum were sensitive in the 2–3 × 10−7M concentration rangem whereas the most sensitive fungal pathogens, such as Rosellinia necatrix, Colletotrichum lagenarium and Fusarium solani, had EC-50 values in the 1−4 × 10−6M range. Thionins, which were not particularly effective in liquid medium against Phytophthora infestans (EC-50=3.9 × 10−5M) were more effective than the fungicide Ridomil on a molar basis in a drop application assay on leaf discs from potato

Plant proteinaceous inhibitors of proteinases and alpha-amylases

Plant proteins which are inhibitory towards various types of enzymes from a wide range of organisms have been extensively studied for many years. Proteinas e inhibitors have received particular attention and accordingly a number of reviews concerning their structure, activity, evolution, possible physiological roles and nutritional properties have appeared regularly in the literature (Ryan, 1973, 1981, 1984; Laskowski and Kato, 1980; Richardson, 1981; Boisen, 1983). Recent technical advances in molecular biology have accelerated the output of information about these inhibitors to the extent that entirely new types have been uncovered and previously unsuspected relationships have been established. These developments justify the present review that will emphasize the novel aspects, glossing over many important topics that have been adequately covered before. Among the most striking recent findings is the structural and evolutionary relationships of different ct-amylase inhibitors with different types of proteinase inhibitors, which is the reason for their joint consideration in this survey