Alternative Splicing Regulation During Light-Induced Germination of Arabidopsis thaliana Seeds (original) (raw)

Acute Effects of Light on Alternative Splicing in Light-Grown Plants

Photochemistry and Photobiology, 2015

Light modulates plant growth and development to a great extent by regulating gene expression programs. Here, we evaluated the effect of light on alternative splicing (AS) in light-grown Arabidopsis thaliana plants using high-throughput RNA sequencing (RNA-seq). We found that an acute light pulse given in the middle of the night, a treatment that simulates photoperiod lengthening, affected AS events corresponding to 382 genes. Some of these AS events were associated with genes involved in primary metabolism and stress responses, which may help to adjust metabolic and physiological responses to seasonal changes. We also found that several core clock genes showed changes in AS in response to the light treatment, suggesting that light regulation of AS may play a role in clock entrainment. Finally, we found that many light-regulated AS events were associated with genes encoding RNA processing proteins and splicing factors, supporting the idea that light regulates this posttranscriptional regulatory layer through AS regulation of splicing factors. Interestingly, the effect of a red-light pulse on AS of a gene encoding a splicing factor was not impaired in a quintuple phytochrome mutant, providing unequivocal evidence that nonphotosensory photoreceptors control AS in light-grown plants.

Alternative Splicing Substantially Diversifies the Transcriptome during Early Photomorphogenesis and Correlates with the Energy Availability in Arabidopsis

The Plant cell, 2016

Plants use light as source of energy and information to detect diurnal rhythms and seasonal changes. Sensing changing light conditions is critical to adjust plant metabolism and to initiate developmental transitions. Here, we analyzed transcriptome-wide alterations in gene expression and alternative splicing (AS) of etiolated seedlings undergoing photomorphogenesis upon exposure to blue, red, or white light. Our analysis revealed massive transcriptome reprogramming as reflected by differential expression of ∼20% of all genes and changes in several hundred AS events. For more than 60% of all regulated AS events, light promoted the production of a presumably protein-coding variant at the expense of an mRNA with nonsense-mediated decay-triggering features. Accordingly, AS of the putative splicing factor REDUCED RED-LIGHT RESPONSES IN CRY1CRY2 BACKGROUND1, previously identified as a red light signaling component, was shifted to the functional variant under light. Downstream analyses of ...

Transcriptional Programs Related to Phytochrome A Function in Arabidopsis Seed Germination

Molecular Plant, 2013

In Arabidopsis seeds, germination is promoted only by phytochromes, principally phytochrome B (phyB) and phytochrome A (phyA). Despite the abundant information concerning the molecular basis of phyB signaling downstream of PIF1/PIL5, the signaling network inducing germination by phyA is poorly known. Here, we describe the influence of phyA on the transcriptome of Arabidopsis seeds when germination is induced by a far-red (FR) pulse. The expression of 11% of the genome was significantly regulated by phyA. Most of the genes were up-regulated and the changes noted late (i.e. 5 h after a FR pulse), whereas changes in down-regulated genes were more abundant earlier (i.e. 0.5 h after a FR pulse). Auxin-and GA-associated elements were overrepresented in the genes that were modified by phyA. A significant number of genes whose expression was affected by phyA had not been previously reported to be dependent on PIL5. Among them, homozygotic mutant seeds of MYB66, a SAUR-like protein, PIN7, and GASA4 showed an impaired promotion of germination by phyA. Natural variation at the transcriptional level was found in early signaling and GA metabolic genes, but not in ABA metabolic and expansin genes between Columbia and Landsberg erecta accessions. Although phyA and phyB/PIL5 signaling pathways share some molecular components, our data suggest that phyA signaling is partially independent of PIL5 when germination is promoted by very low fluences of light. Downloaded from Brose, J. (2009). Jasmonate passes muster: a receptor and targets for the defense hormone. Annu. Rev. Plant Biol. 60, 183-205. seed germination by light-induced histone arginine demethylation activity. Dev. Cell. 22, 736-748. Clarke, J.D., and Zhu, T. (2006). Microarray analysis of the transcriptome as a stepping stone towards understanding biological systems: practical considerations and perspectives. Plant J. 45, 630-650. Czechowski, T., Stitt, M., Altmann, T., Udvardi, M.K., and Scheible, W.R. (2005). Genome-wide identification and testing of superior reference genes for transcript normalization in Arabidopsis. Plant Physiol. 139, 5-17.

DRT111/SFPS splicing factor controls ABA sensitivity in Arabidopsis seed development and germination

RNA splicing is a fundamental mechanism contributing to the definition of the cellular protein population in any given environmental condition. DRT111/SFPS is a splicing factor previously shown to interact with phytochromeB and characterized for its role in splicing of pre-mRNAs involved in photomorphogenesis. Here, we show that DRT111 interacts with Arabidopsis Splicing Factor 1 (SF1), involved in 3’ splicing site recognition. Double and triple mutant analysis shows that DRT111 controls splicing of ABI3 and acts upstream of the splicing factor SUPPRESSOR OF ABI3-5 (SUA). DRT111 is highly expressed in seeds and stomata of Arabidopsis and is induced by long-term treatments with polyethylene glycol and ABA. DRT111 knock-out mutants are defective in ABA-induced stomatal closure and are hypersensitive to ABA during seed germination. Conversely, DRT111 over-expressing plants show ABA hyposensitive seed germination. RNAseq experiments show that in dry seeds, DRT111 controls expression and...

DRT111/SFPS splicing factor controls ABA sensitivity during seed development and germination

Plant Physiology

RNA splicing is a fundamental mechanism contributing to the definition of the cellular protein population in any given environmental condition. DNA-DAMAGE REPAIR/TOLERATION PROTEIN 111/ SPLICING FACTOR FOR PHYTOCHROME SIGNALING (DRT111/SFPS) is a splicing factor previously shown to interact with phytochrome B and characterized for its role in splicing of pre-mRNAs involved in photomorphogenesis. Here, we show that DRT111 interacts with Arabidopsis thaliana Splicing Factor 1 (SF1), involved in 3′ splicing site recognition. Double and triple mutant analysis shows that DRT111 controls splicing of ABI3 and acts upstream of the splicing factor SUPPRESSOR OF ABI3-5 (SUA). DRT111 is highly expressed in seeds and stomata of Arabidopsis and is induced by long-term treatments of polyethylene glycol and abscisic acid (ABA). DRT111 knockout mutants are defective in ABA-induced stomatal closure and are hypersensitive to ABA during seed germination. Conversely, DRT111 over-expressing plants show ABA-hyposensitive seed germination. RNAseq experiments show that in dry seeds, DRT111 controls expression and splicing of genes involved in osmotic-stress and ABA responses, light signaling, and mRNA splicing, including targets of ABSCISIC ACID INSENSITIVE3 (ABI3) and PHYTOCHROME INTERACTING FACTORs (PIFs). Consistently, expression of the germination inhibitor SOMNUS, induced by ABI3 and PIF1, is up-regulated in imbibed seeds of drt111-2 mutants. Together, these results indicate that DRT111 controls sensitivity to ABA during seed development, germination, and stomatal movements, and integrates ABA-and light-regulated pathways to control seed germination.

Light in the transcription landscape: chromatin, RNA polymerase II and splicing throughout Arabidopsis thaliana’s life cycle

Transcription

Plants have a high level of developmental plasticity that allows them to respond and adapt to changes in the environment. Among the environmental cues, light controls almost every aspect of A. thaliana's life cycle, including seed maturation, seed germination, seedling de-etiolation and flowering time. Light signals induce massive reprogramming of gene expression, producing changes in RNA polymerase II transcription, alternative splicing, and chromatin state. Since splicing reactions occur mainly while transcription takes place, the regulation of RNAPII transcription has repercussions in the splicing outcomes. This cotranscriptional nature allows a functional coupling between transcription and splicing, in which properties of the splicing reactions are affected by the transcriptional process. Chromatin landscapes influence both transcription and splicing. In this review, we highlight, summarize and discuss recent progress in the field to gain a comprehensive insight on the cross-regulation between chromatin state, RNAPII transcription and splicing decisions in plants, with a special focus on light-triggered responses. We also introduce several examples of transcription and splicing factors that could be acting as coupling factors in plants. Unravelling how these connected regulatory networks operate, can help in the design of better crops with higher productivity and tolerance.

Phytochrome Control of theArabidopsisTranscriptome Anticipates Seedling Exposure to Light

The Plant Cell, 2005

Phytochromes mediate a profound developmental shift when dark-grown seedlings are exposed to light. Here, we show that a subset of genes is upregulated in phytochrome B (phyB) mutants even before dark-grown Arabidopsis thaliana seedlings are exposed to light. Most of these genes bear the RY cis motif, which is a binding site of the transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3), and the phyB mutation also enhances ABI3 expression. These changes in transcriptome have physiological consequences, because seedlings of the abi3 mutant showed enhanced responses to pulses of far-red light, whereas ABI3 overexpressers exhibited the opposite pattern. Seedlings of the wild type derived from seeds germinated in full darkness showed enhanced expression of genes bearing the RY cis motif and reduced responses to farred light. We propose that, via changes in ABI3 expression, light, perceived mainly by phyB in the seed, generates a downstream transdevelopmental phase signal that preconditions the seedling to its most likely environment.

Phytochrome Control of the Arabidopsis Transcriptome Anticipates Seedling Exposure to Light

Plant Cell, 2005

Phytochromes mediate a profound developmental shift when dark-grown seedlings are exposed to light. Here, we show that a subset of genes is upregulated in phytochrome B (phyB) mutants even before dark-grown Arabidopsis thaliana seedlings are exposed to light. Most of these genes bear the RY cis motif, which is a binding site of the transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3), and the phyB mutation also enhances ABI3 expression. These changes in transcriptome have physiological consequences, because seedlings of the abi3 mutant showed enhanced responses to pulses of far-red light, whereas ABI3 overexpressers exhibited the opposite pattern. Seedlings of the wild type derived from seeds germinated in full darkness showed enhanced expression of genes bearing the RY cis motif and reduced responses to farred light. We propose that, via changes in ABI3 expression, light, perceived mainly by phyB in the seed, generates a downstream transdevelopmental phase signal that preconditions the seedling to its most likely environment.