The plant cell wall-dynamic, strong, and adaptable-is a natural shapeshifter.

Mythology is replete with good and evil shapeshifters, who, by definition, display great adaptability and assume many different forms-with several even turning themselves into trees. Cell walls certainly fit this definition as they can undergo subtle or dramatic changes in structure, assume many shapes, and perform many functions. In this review, we cover the evolution of knowledge of the structures, biosynthesis, and functions of the 5 major cell wall polymer types that range from deceptively simple to fiendishly complex. Along the way, we recognize some of the colorful historical figures who shaped cell wall research over the past 100 years. The shapeshifter analogy emerges more clearly as we examine the evolving proposals for how cell walls are constructed to allow growth while remaining strong, the complex signaling involved in maintaining cell wall integrity and defense against disease, and the ways cell walls adapt as they progress from birth, through growth to maturation, and in the end, often function long after cell death. We predict the next century of progress will include deciphering cell type-specific wall polymers; regulation at all levels of polymer production, crosslinks, and architecture; and how walls respond to developmental and environmental signals to drive plant success in diverse environments.

A century of studying plant secondary metabolism-From "what?" to "where, how, and why?"

Over the past century, early advances in understanding the identity of the chemicals that collectively form a living plant have led scientists to deeper investigations exploring where these molecules localize, how they are made, and why they are synthesized in the first place. Many small molecules are specific to the plant kingdom and have been termed plant secondary metabolites, despite the fact that they can play primary and essential roles in plant structure, development, and response to the environment. The past 100 yr have witnessed elucidation of the structure, function, localization, and biosynthesis of selected plant secondary metabolites. Nevertheless, many mysteries remain about the vast diversity of chemicals produced by plants and their roles in plant biology. From early work characterizing unpurified plant extracts, to modern integration of 'omics technology to discover genes in metabolite biosynthesis and perception, research in plant (bio)chemistry has produced knowledge with substantial benefits for society, including human medicine and agricultural biotechnology. Here, we review the history of this work and offer suggestions for future areas of exploration. We also highlight some of the recently developed technologies that are leading to ongoing research advances.

Enabling Lignin Valorization Through Integrated Advances in Plant Biology and Biorefining.

Despite lignin having long been viewed as an impediment to the processing of biomass for the production of paper, biofuels, and high-value chemicals, the valorization of lignin to fuels, chemicals, and materials is now clearly recognized as a critical element for the lignocellulosic bioeconomy. However, the intended application for lignin will likely require a preferred lignin composition and form. To that end, effective lignin valorization will require the integration of plant biology, providing optimal feedstocks, with chemical process engineering, providing efficient lignin transformations. Recent advances in our understanding of lignin biosynthesis have shown that lignin structure is extremely diverse and potentially tunable, while simultaneous developments in lignin refining have resulted in the development of several processes that are more agnostic to lignin composition. Here, we review the interface between in planta lignin design and lignin processing and discuss the advances necessary for lignin valorization to become a feature of advanced biorefining.

Poplar glutathione S-transferase PtrGSTF8 contributes to reactive oxygen species scavenging and salt tolerance.

Glutathione S-transferases (GSTs) constitute a protein superfamily encoded by a large gene family and play a crucial role in plant growth and development. However, their precise functions in wood plant responses to abiotic stress are not fully understood. In this study, we isolated a Phi class glutathione S-transferase-encoding gene, PtrGSTF8, from poplar (Populus alba × P. glandulosa), which is significantly up-regulated under salt stress. Moreover, compared with wild-type (WT) plants, transgenic tobacco plants exhibited significant salt stress tolerance. Under salt stress, PtrGSTF8-overexpressing tobacco plants showed a significant increase in plant height and root length, and less accumulation of reactive oxygen species. In addition, these transgenic tobacco plants exhibited higher superoxide dismutase, peroxidase, and catalase activities and reduced malondialdehyde content compared with WT plants. Quantitative real-time PCR experiments showed that the overexpression of PtrGSTF8 increased the expression of numerous genes related to salt stress. Furthermore, PtrMYB108, a MYB transcription factor involved in salt resistance in poplar, was found to directly activate the promoter of PtrGSTF8, as demonstrated by yeast one-hybrid assays and luciferase complementation assays. Taken together, these findings suggest that poplar PtrGSTF8 contributes to enhanced salt tolerance and confers multiple growth advantages when overexpressed in tobacco.

Incidence and Impact of Takotsubo Syndrome in Hospitalized Patients With COVID-19.

BACKGROUND: Takotsubo syndrome has been reported in patients with COVID-19, although minimal data are available. This investigation assessed the incidence and impact of takotsubo syndrome on patients hospitalized with COVID-19. METHODS: A retrospective cohort study was conducted using International Statistical Classification of Diseases, Tenth Revision, codes to identify patients with a primary diagnosis of COVID-19 with or without takotsubo syndrome in the National Inpatient Sample 2020 database. Outcomes between groups were compared after propensity score matching for patient and hospital demographics and comorbidities. RESULTS: A total of 211,448 patients with a primary diagnosis of COVID-19 were identified. Of these, 171 (0.08%) had a secondary diagnosis of takotsubo syndrome. Before matching, patients with COVID-19 and takotsubo syndrome, compared with patients without takotsubo syndrome, were older (68.95 vs 64.26 years; P < .001); more likely to be female (64.3% vs 47.2%; P < .001); and more likely to have anxiety (24.6% vs 12.8%; P < .001), depression (17.5% vs 11.4%; P = .02), and chronic obstructive pulmonary disease (24.6% vs 14.7%; P < .001). The takotsubo syndrome group had worse outcomes than the non-takotsubo syndrome group for death (30.4% vs 11.1%), cardiac arrest (7.6% vs 2.1%), cardiogenic shock (12.9% vs 0.4%), length of hospital stay (10.7 vs 7.5 days), and total charges ($152,685 vs $78,468) (all P < .001). After matching and compared with the non-takotsubo syndrome group (n = 508), the takotsubo syndrome group (n = 170) had a higher incidence of inpatient mortality (30% vs 14%; P < .001), cardiac arrest (7.6% vs 2.8%; P = .009), and cardiogenic shock (12.4% vs 0.4%; P < .001); a longer hospital stay (10.7 vs 7.6 days; P < .001); and higher total charges ($152,943 vs $79,523; P < .001). CONCLUSION: Takotsubo syndrome is a rare but severe in-hospital complication in patients with COVID-19.