Autophagy in maternal tissues contributes to Arabidopsis seed development.

Seeds are an essential food source, providing nutrients for germination and early seedling growth. Degradation events in the seed and the mother plant accompany seed development, including autophagy, which facilitates cellular component breakdown in the lytic organelle. Autophagy influences various aspects of plant physiology, specifically nutrient availability and remobilization, suggesting its involvement in source-sink interactions. During seed development, autophagy affects nutrient remobilization from mother plants and functions in the embryo. However, it is impossible to distinguish between the contribution of autophagy in the source (i.e. the mother plant) and the sink tissue (i.e. the embryo) when using autophagy knockout (atg mutant) plants. To address this, we employed an approach to differentiate between autophagy in source and sink tissues. We investigated how autophagy in the maternal tissue affects seed development by performing reciprocal crosses between wild type and atg mutant Arabidopsis (Arabidopsis thaliana) plants. Although F1 seedlings possessed a functional autophagy mechanism, etiolated F1 plants from maternal atg mutants displayed reduced growth. This was attributed to altered protein but not lipid accumulation in the seeds, suggesting autophagy differentially regulates carbon and nitrogen remobilization. Surprisingly, F1 seeds of maternal atg mutants exhibited faster germination, resulting from altered seed coat development. Our study emphasizes the importance of examining autophagy in a tissue-specific manner, revealing valuable insights into the interplay between different tissues during seed development. It also sheds light on the tissue-specific functions of autophagy, offering potential for research into the underlying mechanisms governing seed development and crop yield.

Hematological malignancy-associated pyoderma gangrenosum: evaluating the magnitude of the association.

Background: Hematologic malignancies (HMs) are well-known underlying comorbidities of pyoderma gangrenosum (PG). However, studies quantifying the likelihood of PG after HMs are yet to be performed. Objective: To investigate the bidirectional association between PG and several HMs, namely acute leukemia, chronic leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, and multiple myeloma. Methods: A population-based retrospective cohort study was conducted to study the risk of HMs in patients with PG (n = 302) as compared to age-, sex-and ethnicity-matched control subjects (n = 1,799). A case-control design was used to estimate the likelihood of PG in individuals with a preexisting history of HMs. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were estimated by Cox regression and logistic regression, respectively. Results: The prevalence of preexisting HM was higher in patients with PG than in controls (6.7% vs. 0.9%, respectively). The likelihood of having PG was significantly greater among patients with a history of HM (adjusted OR, 7.88; 95% CI, 3.85-16.15; p < 0.001), particularly during the first year following the diagnosis. This association was significant for acute leukemia, chronic leukemia, non-Hodgkin lymphoma, and multiple myeloma but not for Hodgkin lymphoma. The incidence rate of HM was 3.3 (95% CI, 1.2-7.4) and 1.6 (95% CI, 0.9-2.6)/1,000 person-years among patients with PG and controls, respectively. Relative to controls, patients with PG were not more likely to develop subsequent HM (adjusted HR, 2.22; 95%CI, 0.77-6.45; p = 0.142). Compared to other patients with PG, those with HM-associated PG experienced an increased all-cause mortality rate (adjusted HR, 2.19; 95%CI, 1.09-4.40; p = 0.028). Conclusion: HM, particularly acute leukemia and multiple myeloma, are associated with an elevated likelihood of provoking PG.