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Controlled primary cell wall remodeling allows plant growth under stressful conditions, but how these changes are conveyed to adjust cellulose synthesis is not understood. Here, we identify the TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) proteins as new members of the cellulose synthase complex (CSC) and describe their unique and hitherto unknown dynamic association with the CSC under cellulose-deficient conditions. We find that TTLs are essential for maintaining cellulose synthesis under high-salinity conditions, establishing a stress-resilient cortical microtubule array, and stabilizing CSCs at the plasma membrane. To fulfill these functions, TTLs interact with CELLULOSE SYNTHASE 1 (CESA1) and engage with cortical microtubules to promote their polymerization. We propose that TTLs function as bridges connecting stress perception with dynamic regulation of cellulose biosynthesis at the plasma membrane., Science Advances, 8 (46), ISSN:2375-2548

Brassinosteroids (BRs) form a group of steroidal hormones essential for plant growth, development, and stress responses. BRs are perceived extracellularly by plasma membrane receptor-like kinases that activate an interconnected signal transduction cascade, leading to the transcriptional regulation of BR-responsive genes. TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) genes are specific for land plants, and their encoded proteins are defined by the presence of protein–protein interaction motives, that is, an intrinsic disordered region at the N terminus, six tetratricopeptide repeat domains, and a C terminus with homology to thioredoxins. TTL proteins thus likely mediate the assembly of multiprotein complexes. Phenotypic, molecular, and genetic analyses show that TTL proteins are positive regulators of BR signaling in Arabidopsis (Arabidopsis thaliana). TTL3 directly interacts with a constitutively active BRASSINOSTEROID INSENSITIVE1 (BRI1) receptor kinase, BRI1-SUPPRESSOR1 phosphatase, and the BRASSINAZOLE RESISTANT1 transcription factor and associates with BR-SIGNALING KINASE1, BRASSINOSTEROID INSENSITIVE2 kinases, but not with BRI1-ASSOCIATED KINASE1. A functional TTL3-green fluorescent protein (GFP) shows dual cytoplasmic plasma membrane localization. Depleting the endogenous BR content reduces plasma membrane localization of TTL3-GFP, while increasing BR content causes its plasma membrane relocalization, where it strengthens the association of BR signaling components. Our results reveal that TTL proteins promote BR responses and suggest that TTL proteins may function as scaffold proteins by bringing together cytoplasmic and plasma membrane BR signaling components.

Los cambios recientes producidos en el ámbito de la educación y, particularmente, en la adquisición de segundas lenguas, como son la utilización de metodologías activas y el viraje en el foco de atención de la gramática hacia el vocabulario, son el punto de partida de esta propuesta de innovación didáctica para una clase de ELE. En concreto, este trabajo parte de un método pedagógico donde el aprendizaje de vocabulario se sitúa en el centro del mismo, el método IBI (input-based incremental), y de cómo una herramienta didáctica, la gamificación, puede aumentar su efectividad tanto en resultados de aprendizaje como en términos actitudinales. Para ello, este trabajo realiza una propuesta de innovación didáctica que consiste en seis lecciones enmarcadas en el recorrido del Camino de Santiago inglés., Recent changes in the field of education and, particularly, in the acquisition of second languages, such as the use of active learning and the shift in the focus of attention from grammar to vocabulary, are the origin of this proposal of didactic innovation for a class of Spanish as a foreign language. Specifically, this work is based on a pedagogical method where vocabulary is the centre of learning, the IBI (input-based incremental) method, and how a didactic tool, gamification, can increase its effectiveness both in learning outcomes and in attitudinal terms. To achieve this, the present work makes a proposal of didactic innovation that consists of six lessons framed in the English route of Camino de Santiago.

Brassinosteroids (BRs) form a group of steroidal hormones essential for plant growth, development and stress responses. BR perception at the plasma membrane initiates a series of phosphorylation events enabling the nuclear accumulation and activity of the key transcription factors BZR1 and BES1. Previous studies support that all BR signaling components form an interconnected pathway, although it is not known how these proteins are brought together for the prompt signal transduction from the plasma membrane to the nucleus. Here we report that plant-specific Tetratricopeptide Thioredoxin- Like (TTL) proteins are positive regulators of BR signaling that function as scaffold for the BR signaling components in Arabidopsis. TTL3 directly interacts with BZR1 and the phosphatase BSU1, and associates in vivo with most core components involved in BR signaling, with the exception of the BAK1 coreceptor. TTL3 is mainly localized in the cytoplasm, and BR treatment increases its localization at the plasma membrane. In addition, the expression of TTL3 strengthens the association of BR-signaling components BSK1 and BZR1 at the plasma membrane. Consistent with a role in BR signaling, mutations in TTL3, and related TTL1 and TTL4 genes cause reduced BR responses, and these defects that highly enhanced in a triple ttl1 ttl3 ttl4 mutant. We propose a novel mechanistic model for BR signaling, in which cytoplasmic/nuclear BR components bound to TTL proteins are recruited to the plasma membrane upon BR perception, which in turn allows the assembly of a BR signaling complex with the goal of ensuring dephosphorylation and nuclear accumulation of the transcription factors BZR1 and BES1. Interestingly, this novel TTL scaffold model for BR signaling resembles that of Wnt signaling in metazoans, in which TTL proteins would act similar to Axin1, optimizing signaling efficiency of the cascade by promoting the assembly of the signaling complex at the plasma membrane.