Linked sucrose synthase genes in group-7 chromosomes in hexaploid wheat (Triticum aestivum L.)

Abstract

SUMMARYA cDNA library from developing wheat endosperm was screened for sucrose-synthase clones using a maize cDNA probé corresponding to the Shl locus under non-stringent conditions. Five positive clones were isolated and initially classified into two types on the basis of their relative ability to hybridize with the probé and of their partial restriction maps. Determination of the nucleotide sequences indicated homology between the two types of wheat clones, with type 1 showing higher homology to the maize Shl locus than to type-2 sequences. The inserís cloned in plasmids pST8 (type 1) and pST3 (type 2) were used as probes to determine the chromosomal locations of the two types of genes. DNAs from compensated nulli-tetrasomic and ditelosomic lines of wheat cultivar Chinese Spring were cleaved with EcoRl and analysed in Southern blots. DNA segments of the two types were thus identified in the short arms of chromosomes 7A, 7D, and, possibly, 7B. The two types of linked loci have been designated Ssl and Ss2, respectively.

Differential expression of two types of sucrose synthase-encoding genes in wheat in response to anaerobiosis, cold shock and light

“…The recent availability of the maize Sus sequence (L.C. Hannah, personal communication) has allowed a direct comparison of the wheat Ss2 sequence with that of maize (Table I), which further supports the equivalence proposed by Maraña et al (1988a). Reciprocal hybridization between the cDNA probes used in the genetic mapping made them unsuitable for studying the differential expres- The type-specific probes were obtained from the inserts in cDNA clones pST8 and pST3 (Maraña et al, 1988a), by subcloning their 3' ends.…”

“…The two types of Ssase-encoding genes in wheat (Ssl and Ss2) were established on the basis of the proportion of identical positions in the nt sequences of the corresponding cDNAs with respect to the maize Sh sequence, among other criteria (Maraña et al, 1988a). The wheat Ss2 sequence was more distant from the wheat Ssl than the maize Sh.…”

“…sion of the two types of genes because their messengers were also of the same size (Maraña et al, 1988a). For these reasons, new probes were obtained for Ssl and Ss2 genes that were about 250 bp and 270 bp in length, respectively, and which essentially corresponded to the noncoding 3'-end regions of the cDNAs.…”

Structural Features of the Maize sus1 Gene and Protein

“…Lengths of the various lines are inversely proportional to t h e amourit of relatedness. Letters denote references as follows: a, Wang et al (1992a); b, this report; c, Martinez et al (1993); (I, Marana et al (1988);e, Werr et al (1985); f, Sanchez et al (1992); g, Wang et al, (1992b); h, Kuester et al (1993);ti, omitted;i, Arai et al (1992); j, Solanum tuberosum, Salanoubat and Belliard (1987); k, Arabidopsis thaliana, Chopra et al (1992); I, Marana et al (1988); m, GenBank accession number Z11532.…”

Cloning of cDNA and chromosomal location of genes encoding the three types of subunits of the wheat tetrameric inhibitor of insect ?-amylase

“…The construction and screening of a wheat cDNA library was carried out as described previously [23], Total polysomal RNA from developing endosperm (20 days after pollination) of cv. Chinese Spring was the source of the poly(A) + RNA used.…”