Enhanced pollen tube performance at high temperature contributes to thermotolerant fruit and seed production in tomato.

Rising temperature extremes during critical reproductive periods threaten the yield of major grain and fruit crops. Flowering plant reproduction depends on the ability of pollen grains to generate a pollen tube, which elongates through the pistil to deliver sperm cells to female gametes for double fertilization. We used tomato as a model fruit crop to determine how high temperature affects the pollen tube growth phase, taking advantage of cultivars noted for fruit production in exceptionally hot growing seasons.

Enhanced pollen tube performance at high temperature contributes to thermotolerant fruit production in tomato.

Rising temperature extremes during critical reproductive periods threaten the yield of major grain and fruit crops. Flowering plant reproduction depends on development of sufficient numbers of pollen grains and on their ability to generate a cellular extension, the pollen tube, which elongates through the pistil to deliver sperm cells to female gametes for double fertilization. These critical phases of the life cycle are sensitive to temperature and limit productivity under high temperature (HT).

Light Modulates Ethylene Synthesis, Signaling, and Downstream Transcriptional Networks to Control Plant Development.

The inhibition of hypocotyl elongation by ethylene in dark-grown seedlings was the basis of elegant screens that identified ethylene-insensitive Arabidopsis mutants, which remained tall even when treated with high concentrations of ethylene. This simple approach proved invaluable for identification and molecular characterization of major players in the ethylene signaling and response pathway, including receptors and downstream signaling proteins, as well as transcription factors that mediate the extensive transcriptional remodeling observed in response to elevated ethylene. However, the dark-adapted early developmental stage used in these experiments represents only a small segment of a plant's life cycle.

Identification of Transcriptional and Receptor Networks That Control Root Responses to Ethylene.

Transcriptomic analyses with high temporal resolution provide substantial new insight into hormonal response networks. This study identified the kinetics of genome-wide transcript abundance changes in response to elevated levels of the plant hormone ethylene in roots from light-grown Arabidopsis () seedlings, which were overlaid on time-matched developmental changes. Functional annotation of clusters of transcripts with similar temporal patterns revealed rapidly induced clusters with known ethylene function and more slowly regulated clusters with novel predicted functions linked to root development.

Defluorination of 4-fluorophenol by cytochrome P450(BM₃)-F87G: activation by long chain fatty aldehydes.

Cytochrome P450(BM3)-F87G catalyzed the oxidative defluorination of 4-fluorophenol, followed by reduction of the resulting benzoquinone to hydroquinone via the NADPH P450-reductase activity of the enzyme. The k (cat) and K (m) for this reaction were 71 ± 5 min(-1) and 9.5 ± 1.

Clinical effects of mandibular fixation on cholesterol intake and serum lipids: a case study.

With cholesterol and saturated fat intake strictly controlled and monitored, the opportunity arose to study the effect of stress on the elevation of cholesterol levels (7). Results indicate significant increase in fasting lipids preoperatively (Table 1). Postoperatively, lipid levels dropped immediately and leveled out to a normal range for this patient and were maintained through the 6-month follow-up blood analysis.