The Messenger RNA Population in the Embryonic Axes of Phaseolus vulgaris During Development and Following Germination

Misra, S. and Bewley, J. D. 1985. The messenger RNA populationin the embryonic axes of Phaseolus vulgaris during developmentand following germination.—J. exp. Bot. 36: 1644–1652. Messenger RNAs were extracted from young, mid-maturation, late-maturation,mature-dry, and 20-h-germinated embryonic axes of Phaseolusvulgaris cv. Taylor's Horticultural. They were translated invitro in a rabbit reticulocyte lysate protein synthesizing system.Analysis of the translation products using two-dimensional polyacrylamidegel electrophoresis indicated that there were substantial changesin the messenger RNA populations of developing and germinatingaxes. The number of polypeptides synthesized increased sharplyat 20–22 d after pollination and then declined. Therewas a parallel increase and decrease in the Poly(A)⁺ contentof the seed axis. The analysis showed that certain messageswere present throughout development and were stored in maturedry seed. These messages were degraded upon subsequent rehydration.Some messages appeared during mid-maturation but declined duringlater stages of development and were absent from the matureseed. In the germinating seed a set of messages unique to germinationappeared. Key words: —Seed development, germination, mRNA, in vitro translation, Phaseolus vulgaris     

Analysis of a meristic trait for hybridization in sunfishes (genus Lepomis)

Necessity of a thorought study of hybridization, following the breakdown of reproductive isolating mechanisms between naturally occurring populations, has been felt by biologists in geneeral and ichthyologists in particular. In this connection a formula for ‘hybrid index’ developed mainly by Hubbs & Kuronuma (1942) and Hubbs, Hubbs & Johnson (1943) has widely been in use, to test the assumption of hybridity and to study the mode of inheritance. Misra, Bateson & Keenleyside (1970) gave statistical methods of analysing hybrid indices estimated for characters of the ‘continuous’ type, and also provided a numerical example. Recently Misra (1971) gave a method of doing similar analysis for hybrid indices estimated for meristic characters, but no example was provided, as data were not available to him. This paper presents a study of hybridization in the sunfishes (genus Lepomis) of Pinehurst Lake, Ontario, Canada, based on the number of scales below the lateral line; the primary purpose of the study is to show the complete computational procedure involved in the application of the method of Misra (1971), so that those users of the method who are mainly interested in the applied aspects of the method, can bypass the mathematics easily.     

Differential changes in the electron transport properties of thylakoid membranes during aging of attached and detached leaves, and of isolated chloroplasts

Abstract. Aging of chloroplasts both in vivo and in vitro causes a considerable loss in the 2,6-dichlorophenol indophenol (DCPIP)-Hill reaction with water as electron donor. The loss can be reduced by exogenous electron donors like diphenyl carbazide (DPC). suggestive of aging-induced damage of the oxygen evolving system. Aging also brings about a considerable loss in methylviologen (MV) reduction mediated by Photosystem I (PS I) of chloroplasts with an ascorbate-DCPIP couple as the electron donating system.
The loss in the electron transport ability of the plastids is faster during in vitro compared to in vivo aging of the chloroplasts.
Light protects the photo-electron transport ability of chloroplasts during aging of intact leaves in contrast to its action during aging of the isolated organelles.     

Influence of Soil Moisture on Soil Solution Chemistry and Concentrations of Minerals in the Calcicoles Phleum phleoides and Veronica spicata Grown on a Limestone Soil

Veronica spicata and Phleum phleoides are calcicole plants,mainly occurring on neutral or alkaline soil. An experimentof 16 weeks duration was performed in a glasshouse with theobjective of elucidating the influence of soil moisture levelon soil solution chemistry, and biomass concentrations and uptakeof mineral nutrients by the plants. Seven levels of moisture,corresponding to 35–85% of the water holding capacity(WHC) of the soil, were tested. Soil solution HCO₃, P and Mnconcentrations, and pH, increased, whereas Ca, Mg and Zn concentrationsdecreased, with increasing soil moisture. Concentrations ofK were highest at 50–70% WHC. Concentrations and amountsof P, Zn and Mn in the two species were usually related to soilsolution concentrations; these are elements with low solubilityand availability in calcareous soils. Concentrations of nutrientsin biomass were more influenced by soil moisture in V. spicatathan inP. phleoides . This indicates that P. phleoides is morecapable of controlling its uptake of mineral nutrients, whereasV. spicata is sensitive to variations in soil moisture. It isconcluded that variation in soil moisture regime may greatlyinfluence concentrations of mineral nutrients in calcareoussoil solutions and their uptake by plants. Species able to utilizethese solubility fluctuations may have an advantage in competitionfor nutrients. Variation in soil moisture content might evenbe a prerequisite for adequate acquisition of mineral nutrientsand growth of plants on limestone soils, thereby influencingthe field distribution of native plants among habitats. Copyright1999 Annals of Botany Company Calcareous, calcicole, concentration, mineral, moisture, nutrient, Phleum phleoides, soil, soil solution, uptake, Veronica spicata, water.     

Transformation of Brassica napus L. with a 'Disarmed' Octopine Plasmid of Agrobacterium tumefaciens: Molecular Analysis and Inheritance of the Transformed Phenotype

Phenotypically normal and fertile transgenic Brassica napuscv. Westar plants were obtained following co-cultivation ofstem epidermal explants with an Agrobacterium tumefaciens straincontaining a disarmed octopine tumour-inducing plasmid pTiB6S3-SE.The A. tumefaciens cells also contained pMON316, a cointegratevector carrying genes for kanamycin resistance and a scorablemarker nopaline synthase. Transformants were selected by theirability to grow in the presence of 100 µg cm^-3 kanamycin.Transformation was confirmed by the activities of neomycin phosphotransferaseII and nopaline synthase enzymes and by Southern blots. Thekanamycin resistance trait was transferred to the progeny ofthe self-fertilized plants. Key words: Transformation, octopine Ti-plasmid, oilseed rape     

Desiccation of Phaseolus vulgaris Seeds During and Following Germination, and its Effect Upon the Translatable mRNA Population of the Seed Axes

Misra, S. and Bewley, J. D. 1986. Desiccation of Phaseolus vulgansseeds during and following germination, and its effect uponthe translatable mRNA population of the seed axes.—J.exp. BoL 37: 364–374. After imbibition and germination, seeds of P. vulgaris passfrom a stage where they are insensitive to desiccation to astage where they are sensitive. Desiccation of seeds duringthe sensitive stage results in an almost total impairment ofprotein synthesis upon subsequent rehydration. Seeds desiccatedduring the desiccation-tolerant stage, however, resume proteinsynthesis at almost control levels. The protein patterns obtained following in Vitro translationof bulk RNA from fresh imbibed, desiccated, and desiccated-rehydratedseed axes were qualitatively similar at 5 HAI (the desiccation-tolerant stage). The drying treatment resulted in increasedintensity of extant proteins at 5 and 12 HAI. At 12 HAI (thetransition stage between the desiccation-tolerant and desiccation-intolerantphases) desiccation and subsequent rehydration triggered synthesisof a unique set of proteins-the rehydration proteins. At 20HAI (the desiccation-intolerant stage) desiccation resultedin an overall decline in the intensity of proteins synthesizedin vitro. Also the rehydration proteins were not synthesizedin response to a drying and rehydration treatment at this time. Key words: Seed germination, desiccation, mRNA, in vitro translation, Phaseolus vulgaris     

A relative growth index of hybridization in sunfishes (genus Lepomis, Centrarchidae)

Sunfish specimens (genus Lepomis) collected from Pinehurst Lake, Ontario, Canada, were identified as bluegill (L. macrochirus), pumpkinseed (L. gibbosus) and their hybrids. Hybridization was studied on the basis of the constants of cross-sectional allometry as, to the best of our knowledge, no attempt has ever been made to study hybridization quantitatively from the relative growth aspect. Two sets of data---one on the pair Y¹/X (head length/standard length) and the other on the pair Y²/X (body depth/standard length)--- were analysed, with the following objectives: (i)A statistical method of analysing hybrid index based on cross-sectional allometry was first presented and then Y¹/X-data analysed by this method, and (ii)data Y²/X were analysed to show that in some particular situations analysis for hybridization by methods other than the hybrid index appraoch may be more appropriate. Results of the analyses were discussed.