No DREAM, No Offspring: Protein complex may play key role in plant fertility
A protein complex known as DREAM that normally puts the brakes on genes may also be crucial for reproduction in plants, according to new research
Institute of Science and Technology Austria
image:
Arabidopsis thaliana (thale cress) in the pink room at ISTA’s Plant Facility. A protein complex that normally puts the brakes on genes may also be crucial for reproduction in plants, according to new research published in Science Advances.
view moreCredit: © Nadine Poniconi/ISTA
A protein complex that normally puts the brakes on genes may also be crucial for reproduction in plants, according to new research published in Science Advances. In thale cress, DREAM appears to switch on genes during meiosis that are important for the exchange of genetic material. But when the complex is missing, reproductive development becomes defective and fertility is severely reduced.
During meiosis, chromosomes must be distributed with great precision. This requires genes to be active and proteins to be present at the correct location, time, and concentration. Consequently, the entire process needs to be tightly regulated.
As part of her PhD project at the University of Hamburg, molecular biologist and postdoctoral researcher at the Institute of Science and Technology Austria (ISTA) Hasibe Tunçay investigated which molecular regulators control this process in thale cress (Arabidopsis thaliana, A. thaliana).
Her research has shed new light on the importance of the DREAM complex. Since related DREAM complexes also affect reproduction in animals, the findings may point to an evolutionarily conserved mechanism underlying fertility across many organisms.
The research was carried out in collaboration with the Université Paris-Saclay, Fudan University, and South China Agricultural University.
Not all cell divisions are the same
In sexually reproducing organisms, there are two fundamental types of cell division: mitosis and meiosis.
During mitosis, one cell produces two largely identical daughter cells. This process is important for an organism’s development and growth, as well as for tissue renewal and maintenance.
Meiosis, by contrast, produces reproductive cells with half the usual number of chromosomes. The full chromosome set is restored only upon fertilization.
For meiosis to work, genes need to be switched on at the right time so that they can be transcribed into RNA. This RNA can then serve as the blueprint for proteins needed to carry out the process.
Meiosis may be a textbook classic, but how it is transcriptionally regulated in plants is still not fully understood. The molecular switches behind the process—known as transcription factors—first need to be identified.
That was precisely the task Tunçay set out to tackle, using thale cress as her model organism.
The DREAM complex
Studying gene regulation during meiosis was technically challenging. Meiotic cells are located deep inside the plant’s reproductive tissues and can only be isolated in small quantities.
Despite these limitations, Tunçay and her colleagues were able to identify an important molecular regulator: the DREAM complex.
The DREAM complex is a transcription-factor complex that also exists in humans. In somatic cells—non-reproductive cells that proliferate through mitosis—DREAM usually represses gene expression. For example, it can help stop the cell cycle when errors occur and damage needs to be repaired.
Now, Tunçay’s research shows that DREAM seems to play another role as well.
DREAM wakes up genes
“We studied mutants—plants in which parts of the DREAM complex are missing—and found that pollen and seed production did not function properly,” says Tunçay. “That made it clear to me that DREAM is also important for plant reproduction, apparently by regulating gene expression during meiosis.”
Tunçay identified the gene MER3, which is activated by the DREAM complex. The resulting MER3 protein plays an important role in crossover formation, a process essential for meiosis.
During a crossover, homologous chromosomes—one inherited from the maternal and one from the paternal side—exchange genetic material.
“This mechanism does not just generate genetic diversity,” Tunçay explains. “It also keeps chromosomes physically connected, allowing them to be distributed correctly to daughter cells during the first meiotic division.”
In mutants in which the DREAM complex does not function properly, MER3 is not transcribed sufficiently. As a result, crossover formation is impaired: chromosomes do not remain connected for long enough and instead occur as individual chromosomes.
“These are called univalent chromosomes,” says Tunçay. These can then be distributed incorrectly or randomly among daughter cells, she adds, producing reproductive cells with an unbalanced number of chromosomes—and ultimately leading to fertility problems.
“In some of our mutants where only a single DREAM complex-component was disrupted, seed production was severely reduced, but the plants remained fertile,” Tunçay explains. “In comparison, mutants carrying disruptions in multiple components produced no seed, indicating that they were sterile.”
But what does that mean for the plant?
Plant sex
A. thaliana is a self-fertilising hermaphroditic plant. Both male stamens and the female pistil are found within the same flower. After fertilisation, the ovary develops into a long, slender fruit called a silique, in which the seeds grow.
Whether mutations affect reproduction can be assessed by examining pollen and seeds.
“For example, you can dip the flower into a solution. This releases the pollen grains, which can then be stained and examined under a microscope to determine whether they are viable,” Tunçay says. “You can also open the silique and assess the seeds inside. Undeveloped or aborted seeds indicate sterility and problems with reproduction.”
The findings show that a known regulatory complex can take on an unexpected activating role during plant meiosis. Because related DREAM complexes also influence reproduction in animals, the results suggest that fertility may be regulated by an evolutionarily conserved mechanism across a wide range of organisms.
Growing Arabidopsis thaliana (thale cress). The DREAM complex might play a key role in the plant’s fertility, according to new research published in Science Advances.
Credit
© ISTA
Journal
Science Advances
Method of Research
Experimental study
Subject of Research
Cells
Article Title
Transcriptional control of meiotic recombination by DREAM complex components
Article Publication Date
16-Oct-2026
Gene and protein mapping offers clues to sweetpotato root enlargement
Maximum Academic Press
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Phylogenetic tree of the NAC gene family.
view moreCredit: Plant Hormones
A research team has mapped a family of plant gene regulators across cultivated sweetpotato and three wild relatives, identifying expression patterns associated with the formation of swollen storage roots or slender “pencil roots.” By combining genome analysis, RNA sequencing, and protein profiling, the researchers highlighted candidate NAC transcription factors and potential hormone signals involved in root development. The findings provide a foundation for investigating how sweetpotato builds its harvestable roots and could eventually support molecular breeding aimed at improving crop yield.
Sweetpotato yield depends on the formation and enlargement of storage roots, a developmental process involving cell division, cell expansion, and changes to cell walls. Previous research has identified genes involved in wall remodeling and starch accumulation, while studies in other crops have established NAC transcription factors as important regulators of growth and stress responses. However, how this gene family contributes to sweetpotato root enlargement remains poorly understood. The crop's complex hexaploid genome further complicates investigation, and wild relatives differ substantially in their capacity to produce swollen roots. Comparing these contrasting plants offers an opportunity to identify regulatory patterns associated with successful storage root development.
A study (DOI: 10.48130/ph-0026-0022) published in Plant Hormones on 29 September 2026 by Ming Li's & Wei Jian's team, Chongqing Normal University, identifies conserved NAC gene families alongside contrasting expression patterns and hormone-responsive promoter elements that suggest candidate mechanisms underlying differences in root swelling.
The researchers compared diploid Ipomoea trifida Y22, wild tetraploid I. batatas Y428B, wild hexaploid I. batatas Y601, and the cultivated variety Nancy Hall. They screened genome-derived protein sequences using sequence similarity searches, NAC-domain models, and conserved-domain verification, then analyzed evolutionary relationships, protein motifs, chromosome locations, and corresponding genomic regions. This workflow identified 134, 142, 132, and 126 NAC genes, respectively: 534 genes in total, grouped into 19 subfamilies and distributed unevenly across 15 chromosomes in each genome. Comparative analysis revealed 292 collinear gene pairs, demonstrating extensive conservation across the four materials. To examine developmental activity, the team collected roots at four stages, from adventitious roots to mature storage roots, with three biological replicates per sampling point. Y428B, which produces pencil roots rather than swollen storage roots, was sampled at matching time points. RNA sequencing revealed that many NAC genes in the three storage-root-forming materials increased their expression as roots developed. In Y428B, most instead showed high early expression followed by a sharp decline, with few displaying sustained increases. The team then used four-dimensional data-independent acquisition proteomics to examine mature-stage roots, detecting 15 NAC proteins across the materials, with three to five detected in each. This limited detection contrasted with the broader transcript profiles, indicating that RNA abundance alone does not fully describe NAC protein accumulation. Iba4xNAC028 was especially abundant in Y428B, while the related proteins Ibw6xNAC022 and Itr2xNAC069 were prominent in wild materials with weaker swelling than Nancy Hall. These associations identify candidates for testing, rather than establish their functions. Finally, analysis of 2,000-base-pair promoter regions for the 15 protein-detected genes found widespread hormone-responsive elements. Sites associated with abscisic acid and methyl jasmonate were most prevalent, while gibberellin-responsive elements were also common, suggesting possible connections between hormone signaling, developmental regulation, and stress responses during root enlargement that merit further experimental investigation.
Together, the findings provide a comparative resource for exploring sweetpotato storage root development. They suggest that differences in when NAC genes become active, which proteins accumulate, and how genes respond to hormonal signals may help explain contrasting root forms. Future hormone-treatment experiments and genetic validation will be needed to determine whether these candidates can be used to improve storage root growth and yield.
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References
DOI
Original Source URL
https://doi.org/10.48130/ph-0026-0022
Funding information
This work was supported by the College Students' Innovation Training Program of Chongqing (No. S202510637033) and the Chongqing Normal University Foundation (No. 23XLB033).
About Plant Hormones
Plant Hormones (e-ISSN 3067-221X) is an open access, online-only, academic journal publishing rigorously peer-reviewed original articles, reviews, break-through methods, editorials, and perspectives on broad aspects of plant hormone biosynthesis, signal transduction, and crosstalk. The journal primarily publishes fundamental research that represents significant advances or new insight into specialized areas of plant hormones, and review articles that provide comprehensive and critical review of current research areas and offer directions or perspectives for future research. The journal publishes applied research that has significant implications for the development of agriculture, horticulture, and forestry. Plant Hormones also provides a community forum by publishing editorials and perspective papers for expressing opinions on specific issues or new perspectives about existing research on particular topics. Plant Hormones is hosted by Chongqing University, and published by Maximum Academic Press.
Journal
Plant Hormones
Subject of Research
Not applicable
Article Title
Genome-wide identification of NAC transcription factors in four 'sweetpotato' species and its transcriptomic and proteomic analysis during storage root development
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