Arabidopsis Sar1b is critical for pollen tube growth.

Pollen tube growth is an essential step leading to reproductive success in flowering plants, in which vesicular trafficking plays a key role. Vesicular trafficking from endoplasmic reticulum to the Golgi apparatus is mediated by the coat protein complex II (COPII). A key component of COPII is small GTPase Sar1. Five Sar1 isoforms are encoded in the Arabidopsis genome and they show distinct while redundant roles in various cellular and developmental processes, especially in reproduction. Arabidopsis Sar1b is essential for sporophytic control of pollen development while Sar1b and Sar1c are critical for gametophytic control of pollen development. Because functional loss of Sar1b and Sar1c resulted in pollen abortion, whether they influence pollen tube growth was unclear. Here we demonstrate that Sar1b mediates pollen tube growth, in addition to its role in pollen development. Although functional loss of Sar1b does not affect pollen germination, it causes a significant reduction in male transmission and of pollen tube penetration of style. We further show that membrane dynamics at the apex of pollen tubes are compromised by Sar1b loss-of-function. Results presented provide further support of functional complexity of the Sar1 isoforms.

Essential oils for managing anthracnose in mango (Mangifera indica): laboratory results do not translate into field efficacy.

Essential oil-based products with broad plant disease control claims are commercially available and may be a practical alternative to copper fungicides for crop protection in organic mango orchards. We evaluated the disease control efficacy and crop safety of thyme oil, savory oil, and tree tea oil through replicated in vitro, in vivo (detached leaf and potted trees), and field assays. Three Colletotrichum species associated with mango anthracnose were tested in vitro, whereas only C. siamense was used for in vivo assays. Within the range of concentrations tested in vitro (62.5 to 2,000 µl a.i./liter), thyme and savory oil displayed fungicidal activity, whereas no fungistatic or fungicidal activity was observed with tea tree oil. In the in vivo assays, none of the treatments based on a preventive application rate of thyme (1,150 µl a.i./liter), savory (2,000 µl a.i./liter), or tea tree oil (342 µl a.i./liter) were effective in preventing the development of anthracnose on wounded and artificially inoculated leaves. Although field applications of thyme or tea tree oil did not result in phytotoxicity or negative impacts on fruit yield, they were ineffective in reducing the incidence and severity of naturally occurring anthracnose. Applications of copper hydroxide approved for organic agriculture were effective in controlling anthracnose in the field, and no added benefits were found by premixing this compound with thyme oil. Results indicate that essential oil products based on thyme or tea tree oil are inefficient at controlling anthracnose in mangoes.

A Comprehensive Analytical Review of Polyphenols: Evaluating Neuroprotection in Alzheimer's Disease.

Alzheimer's Disease (AD), a prevalent neurodegenerative disorder, is the primary cause of dementia. Despite significant advancements in neuroscience, a definitive cure or treatment for this debilitating disease remains elusive. A notable characteristic of AD is oxidative stress, which has been identified as a potential therapeutic target. Polyphenols, secondary metabolites of plant origin, have attracted attention due to their potent antioxidant properties. Epidemiological studies suggest a correlation between the consumption of polyphenol-rich foods and the prevention of chronic diseases, including neurodegenerative disorders, which underscores the potential of polyphenols as a therapeutic strategy in AD management. Hence, this comprehensive review focuses on the diverse roles of polyphenols in AD, with a particular emphasis on neuroprotective potential. Scopus, ScienceDirect, and Google Scholar were used as leading databases for study selection, from 2018 to late March 2024. Analytical chemistry serves as a crucial tool for characterizing polyphenols, with a nuanced exploration of their extraction methods from various sources, often employing chemometric techniques for a holistic interpretation of the advances in this field. Moreover, this review examines current in vitro and in vivo research, aiming to enhance the understanding of polyphenols' role in AD, and providing valuable insights for forthcoming approaches in this context.