bloom dynamics depend principally on the impact of consumers, a long-recognized control of phytoplankton abundance (30). Our findings for Synechococcus agree with those of Behrenfeld and Boss in so far as division rates (and, by inference, loss rates) are roughly 10 times the accumulation (net growth) rates. Our results differ, however, in that we find a significant positive correlation between division and accumulation rates over the course of the spring bloom (Fig. 4, B and C). This correlation was not detected by Behrenfeld and Boss, and perhaps should not be expected to be evident in the satellite-based observations of chlorophyll concentration that they analyzed (29). Those observations aggregate the entire phytoplankton community over a relatively large region of the ocean and mask individual responses of different taxa.Our observations, made at a much smaller spatial scale and with much finer taxonomic and temporal resolution than that of satellite data, reveal a connection between division rates and the bloom dynamics of Synechococcus. Consumers (including grazers, viruses, and parasites) certainly play a major role in shaping the bloom's trajectory, but the bloom is triggered by an environmental factor, the seasonal temperature rise, which leads to increases in the Synechococcus division rate (Fig. 3). The bloom persists until the division rate plateaus (Fig. 4B), at which point losses overtake division and the bloom begins to decline.We were able to diagnose the importance of temperature in regulating the dynamics of a ubiquitous marine primary producer, Synechococcus, by exploiting a 13-year time series comprising data on millions of individual cells and their traits. This allowed us to not only quantify the relationship between temperature and cell division in a natural population, but also to document how that relationship is the basis for a dramatic phenological shift affecting both Synechococcus and their consumers. It remains to be seen whether this ecological coupling will hold as warming trends continue in the decades to come.

One step conversion of lignin from intact biomass to two phenol products, improving access to aromatics and fuels.

We identified a dwarf transgenic hybrid poplar (Populus tremula × Populus alba) after screening of 627 independent activation-tagged transgenic lines in tissue culture, greenhouse, and field environments. The cause of the phenotype was a hyperactivated gene encoding GA 2-oxidase (GA2ox), the major gibberellin (GA) catabolic enzyme in plants. The mutation resulted from insertion of a strong transcriptional enhancer near the transcription start site. Overexpression of the poplar GA2ox gene (PtaGA2ox1) caused hyperaccumulation of mRNA transcripts, quantitative shifts in the spectrum of GAs, and similarity in phenotype to transgenic poplars that overexpress a bean (Phaseolus coccineus) GA2ox gene. The poplar PtaGA2ox1 sequence was most closely related to PsGA2ox2 from pea (Pisum sativum) and two poorly known GA2oxs from Arabidopsis (AtGA2ox4 and AtGA2ox5). The dwarf phenotype was reversible through gibberellic acid application to the shoot apex. Transgenic approaches to producing semidwarf trees for use in arboriculture, horticulture, and forestry could have significant economic and environmental benefits, including altered fiber and fruit production, greater ease of management, and reduced risk of spread in wild populations.