Binding of GTP‐binding proteins with [35S]GTP7S in the extract containing membrane components of Lemna paucicostata 441 was inhibited by red or far red light by 20 to 25%, but blue light showed no or little effect. The plant used for the preparation of the extract was subjected to single darkness for 8 h, as both red and far red light inhibit flowering. The extract treated with 1% Lubrol was fractionated by gel filtration. Four species of GTP‐binding proteins, GL1, GL2, GL3 and GL4 were detected with Km values 3, 7, 80 and 4 nM, respectively. GL1, GL2 and GL3 were ADP‐ribosylated by pertussis toxin. The extract activated by [35S]GTP‐γS in darkness, under red light or under far red light was treated with 1% Lubrol and subsequent gel filtration of the extracts made it possible to detect GTP‐binding protein with a small molecular weight only in an extract labeled in darkness. The reduction in the molecular weight of GTP‐binding protein from the larger molecule associated with the binding of [35S]GTPγS was confirmed by rechromatography of the larger molecule activated by [35S]GTPγS in darkness. The binding of GL2 and/or GL3 with [35S]GTPγS was suggested to be inhibited by red or far red light.

Wild-type plants of the Japanese morning glory (Ipomoea nil) produce blue flowers that accumulate anthocyanin pigments, whereas its mutant cultivars show wide range flower color such as red, magenta and white. However, I. nil lacks yellow color varieties even though yellow flowers were curiously described in words and woodblocks printed in the 19th century. Such yellow flowers have been regarded as ‘phantom morning glories’, and their production has not been achieved despite efforts by breeders of I. nil. The chalcone isomerase (CHI) mutants (including line 54Y) bloom very pale yellow or cream-colored flowers conferred by the accumulation of 2′, 4′, 6′, 4-tetrahydoroxychalcone (THC) 2′-O-glucoside. To produce yellow phantom morning glories, we introduced two snapdragon (Antirrhinum majus) genes to the 54Y line by encoding aureusidin synthase (AmAS1) and chalcone 4′-O-glucosyltransferase (Am4′CGT), which are necessary for the accumulation of aureusidin 6-O-glucoside and yellow coloration in A. majus. The transgenic plants expressing both genes exhibit yellow flowers, a character sought for many years. The flower petals of the transgenic plants contained aureusidin 6-O-glucoside, as well as a reduced amount of THC 2′-O-glucoside. In addition, we identified a novel aurone compound, aureusidin 6-O-(6″-O-malonyl)-glucoside, in the yellow petals. A combination of the coexpression of AmAS1 and Am4′CGT and suppression of CHI is an effective strategy for generating yellow varieties in horticultural plants.

No abstract

No abstract

An efficient isolation method for meiotic mutants causing meiotic nondisjunction An efficient isolation method for meiotic mutants causing meiotic nondisjunction or elevated recombination frequency in Neurospora crassa. or elevated recombination frequency in Neurospora crassa.