A key mechanism utilized by plants to make iron (Fe) available for
uptake is the reduction of Fe(III) to Fe(II) via an inducible, plasma
membrane-bound Fe(III) reductase. Genes encoding such enzymes have
not yet been isolated from plants; however, two Fe(III) reductases have
been cloned from yeast. FRE1 and FRE2...
Cytokinins are plant hormones regulating cell division and differentiation.
Most developmental events from germination, vegetative morphogenesis to seed
and fruit set are influenced by cytokinins. t,ns-Zeatin is the major natural
occurring cytokinin. Its isomer, cis-zeatin, and its derivatives are usually present in
low quantities and have traditionally been considered as...
Conversion of exogenous cis-zeatin to trans-zeatin in immature seeds of
Phaseolus vulgaris L. led to the isolation of a cis-trans isomerase from the endosperm.
The enzyme was purified over 2000-fold by chromatography on a series of FPLC
(anion exchange, gel filtration, and hydrophobic interaction) and Concanavalin A
columns. Non-enzymatic isomerization...
Appropriate micropropagation regimes were developed for four Pyrus species (P.
amygdaliformis Vill., P. betulaefolia Bunge, P. calleryana Dcne., and P. communis L.)
and Cydonia oblonga L. Shoot multiplication was optimal at 10 or 20μM N⁶⁻
benzyladenine (BA) and high light intensity (135μm⁻²s⁻1). Root formation of the
Pyrus species was stimulated...
Quince (Cydonia oblonga Mill.) is widely used as a dwarfing rootstock for pear
{Pyrus communis L.). The disadvantage of this rootstock is its inefficient uptake of Fe,
resulting in leaf chlorosis. Application of tissue culture and gene transfer techniques may
lead to production of quince clones with improved Fe efficiency....
Phaseolus vulgaris, the common bean, is susceptible to many
bacterial, fungal and viral diseases. However, resistance to several
diseases has been identified in related Phaseolus species, P.
coccineus, P. acutifolius and P. lunatus. Thus, interspecific
hybridization could result in transfer of beneficial characteristics.
One of the problems encountered in interspecific...
Cytokinins can be conjugated to N- and O-glucosides. While N-glucosylation generally leads to irretrievable loss of activity, O-glucosides are thought to play an important role in cytokinin storage and homeostasis since they can be hydrolyzed to the corresponding aglycones. The first zeatin O-glycosyltransferase genes isolated were ZOG1 and ZOX1 from...