sym 13—A Gene Conditioning Ineffective Nodulation in Pisum sativum

Abstract

Treatment of Pisum sativum (L.) cv. 'Sparkle' with ethyl methanesulfonic acid (EMS) produced a stable mutant, E135F, which forms small, white, ineffective nodules. These nodules exhibit histological zonation typical of an indeterminant nodule, e.g. meristematic, early symbiotic, late symbiotic, and senescent zones. Compared with the nitrogen fixing nodules of the parent, the zones are smaller and the nodules senesce prematurely. Bacteroids in E135F are less elongated and less differentiated than those in 'Sparkle.' The E135F mutant forms ineffective nodules when inoculated with nine different effective strains of Rhizobium leguminosarum and also when grown in a soil containing effective strains. The ineffective phenotype of E135F is under monogenic recessive control; the gene is designated sym 13. sym 13 was located on chromosome 2 by linkage with genes for shikimic dehydrogenase and esterase-2. The original selection E135F carried another mutation in heterozygous form at a separate locus, yielding some homozygous recessive nonnodulating progeny, E135N, in (14) with ineffective nodules have been discovered in breeding programs. In addition, ineffective lines of chickpea (Cicer arietinum L.) (1), faba bean (Vicia faba L.) (4), and pea (Pisum sativum L.) (3, 15) have been obtained by induced mutagenesis.This report describes an ineffective mutant of pea obtained

Non-nodulating Mutants of Pisum Sativum (L.) cv. Sparkle

“…(This portion of the genome was previously assigned to chromosome 2 [Blixt 1974]. ) E135, a phenotypically different mutant with nonfixing nodules, is conditioned by syml3, which also is in this region (Kneen et al 1990a). …”

“…We have induced a large set of pea mutants that are defective in nodulation (Kneen et al 1984(Kneen et al ,1987(Kneen et al , 1990a, and are using them to characterize the symbiosis (sym) genes of the host plant. Except for nodulation, most of our mutants look normal (Kneen et al 1984(Kneen et al , 1990a. If provided with nitrate, their growth habit is no different than that of the normal nodulating parent Sparkle.…”

Novel series os pea symbiotic mutants induced in the SGE line

“…При проведении комплементационного анализа Fix -мутантов в качестве тестерных линий были использованы Fix-мутанты из коллекции ГНУ ВНИИСХМ (http://www. arriam.spb.ru/rus/lab9/collections.html), представляющие все идентифицированные к настоящему времени гены, контролирующие поздние стадии развития клубеньков: sym13 (E135f) (индуцирована на сорте Sparkle) (Kneen et al, 1990), sym23 (p59), sym24 (p60), sym25 (p61), sym27 (p12) (индуцированы на сорте Frisson) (Sagan et al, 1993), sym31 (индуцирована на лабораторной ли-нии Sprint-2) (Borisov et al, 1992), sym33 (SGEFix --2), sym40 (SGEFix --1) (индуцированы на лабораторной ли-нии SGE) (Tsyganov et al, 1994), sym32 (RisFixL), sym41 (RisFixa) и sym42 (RisFixV) (индуцированы на сорте Finale) (Engvild, 1987). Для проведения тестов на алле-лизм каждый выявленный мутант, вовлеченный в компле-ментационный анализ, был реципрокно скрещен со всеми тестерными линиями.…”

“…Ранее в литературе были описаны случаи возникновения в геноме после экспериментального ЭМС-мутагене-за мутаций в двух различных симбиотических генах. Так, гибридологический анализ мутанта гороха E135F (sym13), характеризующегося Fix -фенотипом, пока-зал, что растения данной линии несут в гетерозиготе рецессивную мутацию в другом гене -sym14, опре-деляющую Nod -фенотип (Kneen et al, 1990). После экспериментального ЭМС-мутагенеза растений Lotus japonicus (Regel.)…”

Nod Factors Induce Nod Factor Cleaving Enzymes in Pea Roots. Genetic and Pharmacological Approaches Indicate Different Activation Mechanisms

“…Plants were pretreated with 10 26 M NodRlv factors overnight and the extracellular NF hydrolase Kneen et al (1990) activity assayed with the substrate NodSm-V(C 16:2 , S). As shown in Figure 2 (chromatograms A and B), a pretreatment with NodRlv factors stimulated the NodSm-II(C 16:2 ) forming activity in wild-type plants.…”