Genetic diversity of the cytoplasm in Triticum and Aegilops

Summary Twelve kinds of common wheat nuclei were placed into the cytoplasms of 23 species of Aegilops and Triticum by repeated backcrosses in the Laboratory of Genetics, Kyoto University. Using these nucleus-cytoplasm hybrids, the distribution of the variegation-inducing cytoplasms was investigated. The variegation was maternally inherited, and was found to be temperature-dependent; it was expressed only at low temperatures, accompanied by a remarkable reduction in the content of chlorophyll a and b, and recovered to almost normal level in a greenhouse kept at 25 °C. The variegation was expressed only by special combinations of the wheat nuclei and alien cytoplasms; nine common wheat nuclei, Tve, P168, CS, N26, Slm, Sk, S615, Sphr, and Splt, and six cytoplasms, T. boeoticum, Ae. umbellulata, Ae. triuncialis, Ae. biuncialis, Ae. columaris, and Ae. triaristata 6x, expressed weak to strong variegation in almost all combinations. Combinations of three common wheat nuclei (JF , Comp and Macha) and 17 other cytoplasms showed no variegation: JF , Comp and Macha appeared to have a sort of restoring gene(s) against variegation. Since distribution of the variegation-inducing cytoplasms was confined to the A and C^u type plasmas, it was assumed that the plasmagene(s) responsible for the variegation originated in the diploid level and was transmitted from Ae. umbellulata to three tetraploid and one hexaploid species of Polyeides section through the process of amphidiploidization.Contribution from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University, No. 399. The present work was supported in part by a Grant-in-Aid (No. 036023) from the Ministry of Education, Japan.     

Nonradioactive labeling with chemically modified cytosine tails by the polymerase chain reaction.

We developed a modified nonradioactive method for the detection of DNA. This method makes use of the polymerase chain reaction for preparation of probes; that is, a DNA fragment inserted in the polylinker region of an M13 or pUC vector is amplified with primers that have a modified cytosine tail at the 5' terminus (C-tailed primers). By this method, large amounts of labeled probes can be obtained easily. After hybridization, modified cytosine tails can be detected immunologically. DNA labeled by this method could be used in plaque hybridization. We could detect 0.05 pg of dot-blotted labeled DNA in 30 min with an enzyme-catalyzed chemiluminescence reaction.     

Synthesis of deoxynucleoside-5'-tri-3'-diphosphates by Streptomyces adephospholyticus ATP:nucleotide pyrophosphokinase

ATP: nucleotide pyrophosphokinase (EC 2.7.6.4.) of Streptomyces adephospholyticus catalyzes an efficient transfer of the 5′-β,γ-pyrophosphoryl group of dATP to the four common deoxynucleoside-5′-triphosphates at their 3′-OH positions in the alkaline pH and in the presence of Co²⁺ ions, giving the respective 3′-pyrophosphoryl derivatives. Deoxyadenosine-5′-tri-3′-diphosphate was chromatographically prepared and structurally characterized.     

Light-Independent and Tissue-Specific Accumulation of Light-Harvesting Chlorophyll a/b Binding Protein and Ribulose Bisphosphate Carboxylase in Dark-Grown Pine Seedlings

The presence of light-harvesting chlorophyll a/b binding proteinsand the small and large subunits of ribulose bisphosphate carboxylasewas revealed in dark-grown pine seedlings. The light-independentaccumulation of the proteins was observed in photosyntheticand/or green tissue, such as cotyledons and hypocotyls, butnot in non-photosynthetic roots. ¹ This work was supported by Grants-in-Aid from the Ministryof Agriculture, Forestry and Fisheries of Japan (IntegratedResearch Program for the Use of Biotechnological Proceduresfor Plant Breeding), and from the Science and Technology Agencyof Japan (Encouragement of Basic Research). (Received May 2, 1991; Accepted August 13, 1991)