Biology subjects

Serrano-Mislata, A.

Publications and source records attributed to Serrano-Mislata, A..

3 recordsLinked to original sources

bioRxiv2021

Coordination between growth and stress responses by DELLA in the liverwort Marchantia polymorpha

Plant survival depends on the optimal use of resources under variable environmental conditions. Among the mechanisms that mediate the balance between growth, differentiation and stress responses, the regulation of transcriptional activity by DELLA proteins stands out. In angiosperms, DELLA accumulation promotes defense against biotic and abiotic stress and represses cell division and expansion, while loss of DELLA function is associated with increased plant size and sensitivity towards stress1. Given that DELLA protein stability is dependent on gibberellin (GA) levels2, and GA metabolism is influenced by the environment3, this pathway is proposed to relay environmental information to the transcriptional programs that regulate growth and stress responses in angiosperms4,5. However, DELLA genes are also found in bryophytes, whereas canonical GA receptors appeared only in vascular plants6-10. Thus, it is not clear whether these regulatory functions of DELLA predated or emerged with typical GA signaling. Here we show that, as in vascular plants, the only DELLA in the liverwort Marchantia polymorpha also participates in the regulation of growth and key developmental processes, and promotes the tolerance towards oxidative stress. Moreover, part of these effects is likely caused by the conserved physical interaction with the MpPIF transcription factor. Therefore, we suggest that the role in the coordination of growth and stress responses was already encoded in DELLA from the common ancestor of land plants, and the importance of this function is justified by its conservation over the past 450 M years.

plant biology↗

bioRxiv2021

The making of cauliflowers: the story of unsuccessful flowers

The arrangement of plant organs, called phyllotaxis, produce remarkable spiral or whorled patterns. Cauliflowers present a unique phyllotaxis with a multitude of spirals over a wide range of scales. How such a self-similar fractal organization emerges from developmental mechanisms has remained elusive. Combining experimental assays with modeling, we found that cauliflowers arise due to the hysteresis of the bistable floral network that generates inflorescences imprinted by a transient floral state. We further show how additional mutations affecting meristem growth dynamics can induce the production of conical phyllotactic structures reminiscent of the conspicuous fractal Romanesco shape. This study reveals how the spectacular morphological modification of the inflorescences in cauliflower and Romanesco shape arises from the hysteresis of the genetic programs controlling inflorescence development. One Sentence SummaryThe molecular making of cauliflowers

plant biology↗

bioRxiv2021

A genetic approach to dissect the role of prefoldins in Arabidopsis

The prefoldin complex (PFDc) was identified in humans as co-chaperone of the cytosolic chaperonin TRiC/CCT. It is conserved in eukaryotes and is composed of subunits PFD1 to 6. PFDc-TRiC/CCT operates folding actin and tubulins. In addition to this function, PFDs participate in a wide range of cellular processes, both in the cytoplasm and in the nucleus, and their malfunction cause developmental alterations and disease in animals, and altered growth and environmental responses in yeast and plants. Genetic analyses in yeast indicate that not all functions performed by PFDs require the participation of the canonical complex. The lack of systematic genetic analyses in higher eukaryotes makes it difficult to discern whether PFDs participate in a particular process as canonical complex or in alternative configurations, i.e. as individual subunits or in other complexes. To tackle this question, and on the premise that the canonical complex cannot be formed if one subunit is missing, we have prepared an Arabidopsis mutant deficient in the six prefoldins, and compared various growth and environmental responses with those of the individual pfd. In this way, we demonstrate that the PFDc is required to delay flowering, for seed germination, or to respond to high salt stress, whereas two or more PFDs redundantly attenuate the response to osmotic stress. A coexpression analysis of differentially expressed genes in the sextuple mutant has identified several transcription factors, such as ABI5 or PIF4, acting downstream of PFDs. Furthermore, it has made possible to assign novel roles for PFDs, for instance, in the response to warm temperature.

plant biology↗