Biology subjects

Dantas, L. L. B.

Publications and source records attributed to Dantas, L. L. B..

3 recordsLinked to original sources

bioRxiv2021

Field microenvironments regulate crop diel transcript and metabolite rhythms

O_LIMost research in plant chronobiology was done in laboratory conditions. However, they usually fail to mimic natural conditions and their slight fluctuations, highlighting or obfuscating rhythmicity. High-density crops, such as sugarcane (Saccharum hybrid), generate field microenvironments with specific light and temperature due to mutual shading. C_LIO_LIWe measured the metabolic and transcriptional rhythms in the leaves of 4-month-old (4 mo) and 9 mo sugarcane grown in the field. Most of the assayed rhythms in 9 mo sugarcane peaked >1 h later than in 4 mo sugarcane, including rhythms of the circadian clock gene, LATE ELONGATED HYPOCOTYL (LHY). C_LIO_LIWe hypothesized that older sugarcane perceives dawn later than younger sugarcane due to self-shading. As a test, we measured LHY rhythms in plants on the east and the west side of a field. We also tested if a wooden wall built between lines of sugarcane changed their rhythms. The LHY peak was delayed in the plants in the west of the field or beyond the wall; both shaded at dawn. C_LIO_LIWe conclude that plants in the same field may have different phases due to field microenvironments, impacting important agronomical traits, such as flowering time, stalk weight and number. C_LI

plant biology↗

bioRxiv2019

Alternative splicing of circadian clock genes is temperature regulated in field-grown sugarcane

Alternative Splicing (AS) is a mechanism that generates different mature transcripts from precursor mRNAs (pre-mRNAs) of the same gene. In plants, a wide range of physiological and metabolic events are related to AS, as well as fast responses to changes in temperature. AS is present in around 60% of intron-containing genes in Arabidopsis, 46% in rice and 38% in maize and it is widespread among the circadian clock genes. Little is known about how AS influences the circadian clock of C4 plants, like commercial sugarcane, a C4 crop with a complex hybrid genome. This work aims to test if the daily dynamics of AS forms of circadian clock genes are regulated by environmental factors, such as temperature, in the field. A systematic search for AS in five sugarcane clock genes, ScLHY, ScPRR37, ScPRR73, ScPRR95 and ScTOC1 using different organs of sugarcane sampled during winter, with 4 months old plants, and during summer, with 9 months old plants, revealed temperature- and organ-dependent expression of at least one alternatively spliced isoform in all genes. Expression of AS isoforms varied according to the season. Our results suggest that AS events in circadian clock genes are correlated with temperature.

plant biology↗

bioRxiv2019

Rhythms of Transcription in Field-Grown Sugarcane Are Highly Organ Specific

We investigated whether different specialized organs in field-grown sugarcane follow the same temporal rhythms in transcription. We assayed the transcriptomes of three organs during the day: leaf, a source organ; internodes 1 and 2, sink organs focused on cell division and elongation; and internode 5, a sink organ focused on sucrose storage. The leaf had twice as many rhythmic transcripts (>68%) as internodes, and the rhythmic transcriptomes of the two internodes were more similar to each other than to those of the leaves. More transcripts were rhythmic under field conditions than under circadian conditions and most of their peaks were during the day. Among the transcripts that were considered expressed in all three organs, only 7.4% showed the same rhythmic time course pattern. The central oscillators of these three organs -- the networks that generate circadian rhythms -- had similar dynamics with different amplitudes. The differences between the rhythmic transcriptomes in circadian conditions and field conditions highlight the importance of field experiments to understand the plant circadian clock in natura. The highly specialized nature of the rhythmic transcriptomes in sugarcane organs probably arises from amplitude differences in tissue-specific circadian clocks and different sensitivities to environmental cues. One sentence summaryThe rhythmic transcriptome of field-grown sugarcane is highly organ-specific.

plant biology↗