The influence of various colors of soil cover (mulch) on the farred/red (FR/R) ratio in upwardly reflected light and on concentrations of chlorophyll (Chi) and light-harvesting Chi protein were measured under field conditions. The FR/R ratios above green surfaces were higher than over white surfaces. Even though plants (Gossypium hirsutum L. cv PD-1) were grown in full sunlight, those that received higher FR/R ratios in upwardly reflected light were taller and had thinner leaves with higher concentrations of Chi and LHC-11. A controlled environment experiment showed FR/R control of Chi and LHC-11 concentrations. The results illustrate the importance of spectral distribution of reflected light on plant growth and a potential means of altering the chemistry of leaf crops under field conditions. survival among the perceived competition (1 1, 12). For example, plants in higher-density populations receive higher FR/R ratios and develop longer stems, a characteristic that increases the probability of keeping some leaves in sunlight.Since plants respond to the FR/R ratio and they cannot discern the source of an altered ratio, variously colored soils and soil surface covers (mulches) have been studied to determine effects on spectral distribution of upwardly reflected light and the associated effects on plant development (15). The spectral distribution of upwardly reflected light (particularly the FR/R ratio) can influence photosynthate partitioning, which alters shoot/root ratios and the amount of nodulation of soybean (Glycine max L.) (10) as well as the fruit yield of tomatoes (Lycopersicon esculentum Mill.) (5). The present research was undertaken to study the influence of the FR/R ratio in upwardly reflected light on Chl and LHC-II content under field conditions. Controlled environment studies have shown that the ratio ofFR' relative to R light acts through the phytochrome system to regulate stem elongation (6); leaf shape, thickness, and Chl concentration (16)

The primary amine coupling reagents succinimidyl-6-biotinamido-hexanoate (NHS-A-biotin) and sulfosuccinimidyl-6-biotinamido-hexanoate (NHS-LC-biotin) were tested for their ability to selectively label Escherichia coli cell envelope proteins in vivo. Probe localization was determined by examining membrane, periplasmic, and cytosolic protein fractions. Both hydrophobic NHS-A-biotin and hydrophilic NHS-LC-biotin were shown

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Bradyrhizobium japonicum USDA 110 has been shown to contain several genetically similar, naturally occurring colony morphology variants. One of these variants, L2-110, although devoid of symbiotic nitrogen fixation, retains significant levels of ex planta nitrogen fixation ability relative to other symbiotically competent USDA 110 variants (MN-110 and I-110). Interestingly, Northern blot analyses revealed that L2-110 nodules, despite their lack of symbiotic nitrogen fixation, contained 65% the level of mRNA for dinitrogenase (nif DK) and 64% the level of dinitrogenase reductase (nif H) mRNA relative to MN-110 nodules. Western blot analyses of tissue from the same nodules detected 32% the level of dinitrogenase and 31% the level of dinitrogenase reductase in L2-110 relative to MN-110. L2-110 appears to be a new class of mutant based on the complete absence of symbiotic nitrogen fixation (Fix-) and the presence of significant ex planta nitrogen fixation (Nif+).