High Temperature and Humidity Affect Pollen Viability and Longevity in Olea europaea L.

Olea europaea L. is a crop typical of the Mediterranean area that has an important role in economy, society, and culture of this region. Climate change is expected to have significant impact on this crop, which is typically adapted to certain pedo-climatic characteristics of restricted geographic areas. In this scenario, the aim of this study was to evaluate the time-course response of pollen viability to different combinations of temperature and humidity. The study was performed comparing flowering time and pollen functionality of O. europaea from twelve cultivars growing at the same site belonging to the Campania olive collection in Italy. Pollen was incubated at 12 °C, 22 °C, and 36 °C in combination with 50% RH or 100% RH treatments for 5 days. The results highlighted that a drastic loss of pollen viability occurs when pollen is subjected to a combination of high humidity and high temperature, whereas 50% RH had less impact on pollen thermotolerance, because most cultivars preserved a high pollen viability over time. In the ongoing climate change scenario, it is critical to assess the effect of increasing temperatures on sensitive reproductive traits such as pollen viability to predict possible reduction in crop yield. Moreover, the results highlighted that the effect of temperature increase on pollen thermotolerance should be evaluated in combination with other environmental factors such as humidity conditions. The screening of olive cultivars based on pollen thermotolerance is critical in the ongoing climate change scenario, especially considering that the economic value of this species relies on successful fertilization and embryo development, and also that production cycle of Olea europaea can be longer than a hundred years

Simulated microgravity affects directional growth of pollen tubes in candidate space crops

BackgroundLong-term space missions will necessarily require producing viable seeds to be used for plant cultivation over time under altered gravity conditions. Pollen is known to play a key role in determining seed and fruit production over seed-to-seed cycles, but very few studies have evaluated pollen functionality under altered gravity.MethodsWe performed ground-based experiments to test how simulated microgravity can affect the directional growth of pollen tubes as a potential bottleneck in seed and fruit sets. The effect of clinorotation was assessed in the pollen of Solanum lycopersicum L. cv. ‘Micro-Tom’ and Brassica rapa L. var. silvestris, both eligible for cultivation in space. Pollen tube length and tortuosity were compared under 1g and simulated microgravity with a uniaxial clinostat.ResultsThe main results highlighted that simulated microgravity significantly increased pollen tube length and tortuosity compared to 1g conditions. Further, clinorotation prompted a differential effect on pollen germination between S. lycopersicum and B. rapa. A more in-depth analysis evaluating the effect of gravity on the directional growth of pollen tubes excluded gravitropic responses as responsible for the tube tip position reached after germination.DiscussionThis research provides new insights into how altered gravity can interfere with plant reproduction and, in particular, microgametophyte functionality. Our findings represent a basis for further studies aimed at understanding the effect of real microgravity on plant reproduction and developing countermeasures to ensure seed-to-seed cultivation in long-term space missions and achieve self-sufficiency in food supplies from Earth

Very Early PSA Response to Abiraterone in mCRPC Patients: A Novel Prognostic Factor Predicting Overall Survival

BACKGROUND Abiraterone Acetate (AA) is approved for the treatment of mCRPC after failure of androgen deprivation therapy in whom chemotherapy is not yet clinically indicated and for treatment of mCRPC progressed during or after docetaxel-based chemotherapy regimen. The aim of this study is to evaluate the role of early PSA decline for detection of therapy success or failure in mCRPC patients treated with AA in post chemotherapy setting.PATIENTS AND METHODS We retrospectively evaluated 87 patients with mCRPC treated with AA. Serum PSA levels were evaluated after 15, 90 days and then monthly. The PSA flare phenomenon was evaluated, according to a confirmation value at least one week apart. The primary endpoint was to demonstrate that an early PSA decline correlates with a longer progression free survival (PFS) and overall survival (OS). The secondary endpoind was to demonstrate a correlation between better outcome and demographic and clinical patient characteristics.RESULTS We have collected data of 87 patients between Sep 2011 and Sep 2014. Early PSA response (≥ 50% from baseline at 15 days) was found in 56% evaluated patients and confirmed in 29 patients after 90 days. The median progression free survival (PFS) was 5,5 months (4,6-6,5) and the median overall survival (OS) was 17,1 months (8,8-25,2). In early responders patients (PSA RR ≥ 50% at 15 days), we found a significant statistical advantage in terms of PFS at 1 year, HR 0.28, 95%CI 0.12-0.65, p=0.003, and OS, HR 0.21 95% CI 0.06-0.72, p=0.01. The results in PFS at 1 years and OS reached statistical significance also in the evaluation at 90 days.CONCLUSION A significant proportion (78.6%) of patients achieved a rapid response in terms of PSA decline. Early PSA RR (≥ 50% at 15 days after start of AA) can provide clinically meaningful information and can be considered a surrogate of longer PFS and OS

Diabetic ketoacidosis at the onset of disease during a national awareness campaign: a 2-year observational study in children aged 0-18 years

After a previous survey on the incidence of diabetic ketoacidosis (DKA) at onset of type 1 diabetes in children in 2013-2014 in Italy, we aimed to verify a possible decline in the incidence of DKA at onset during a national prevention campaign

The Silent Epidemic of Diabetic Ketoacidosis at Diagnosis of Type 1 Diabetes in Children and Adolescents in Italy During the COVID-19 Pandemic in 2020

To compare the frequency of diabetic ketoacidosis (DKA) at diagnosis of type 1 diabetes in Italy during the COVID-19 pandemic in 2020 with the frequency of DKA during 2017-2019

The role of pollen in plant resilience to climate change

Pollen interaction with the environmental factors represents a potential bottleneck that can drastically limit reproductive success both in rare and in crop species. Among environmental constraints, high temperatures and humidity are well known to affect pollen viability, pollen germinability and fertilization success. Negative effects of high temperature before pollen development have been described on microsporogenesis of several species. Despite the general knowledge on the effect of temperature on plant reproduction, studies aimed at investigating possible implications of heat stress induced aberrations on the later gametogenesis phases have been generally neglected. All research activities carried out during the Ph.D. aimed to bridge this gap of knowledge deepening the effect of the main factors affecting pollen functionality. This approach was applied both to wild species threatened with extinction and to crop species. In the first case the main aim was to contribute at identifying the bottleneck limiting the generation turnover and the long-term conservation of the species. For crops the main goal was to analyse the species resilience to environmental factors in a scenario of climate changes. Additionally, the approach of analysing the interaction between plants and environmental factors was also extended to space factors, and more specifically to altered gravity conditions. These research activities were aimed at contributing to succeed in the long-term mission to Moon and Mars by using plants in Bioregenerative Life Support Systems

TEMPERATURE AND HUMIDITY AFFECT POLLEN VIABILITY AND MAY TRIGGER DISTYLY DISRUPTION IN THREATENED SPECIES

Within the ongoing trend of rapid climate changes there is an urgent need to assess the vulnerability of the endangered species for evaluating their conservation status and planning effective actions. Primula palinuri Petagna is a relict chasmophyte classified as Vulnerable due to its decreasing populations. The species evolved a distylous syndrome: a reproductive system that maintains a high genetic variability by enhancing cross-pollination. Using an experimental approach, we compared the effect of three different temperatures and three levels of relative humidity on pollen viability of both short-styled and long styled flowers of P. palinuri. Data highlighted that temperature and humidity significantly affect pollen viability. Notably, pollen of short-styled flowers showed a significant higher viability than the long-styled morph in any of the tested treatments. Such results raised the concern for distyly equilibrium disruption in this species, a phenomenon that in isolated populations may cause a sharp raising of the risk of local extinction. Overall, results on this Primula species suggest that in a scenario of climate changes the effect of environmental factors on pollen functionality of any endangered distylous species should not be overlooked for their vulnerability assessment and conservation status evaluation

A Machine-Learning Method to Assess Growth Patterns in Plants of the Family Lemnaceae

Numerous new technologies have been implemented in image analysis methods that help researchers draw scientific conclusions from biological phenomena. Plants of the family Lemnaceae (duckweeds) are the smallest flowering plants in the world, and biometric measurements of single plants and their growth rate are highly challenging. Although the use of software for digital image analysis has changed the way scientists extract phenomenological data (also for studies on duckweeds), the procedure is often not wholly automated and sometimes relies on the intervention of a human operator. Such a constraint can limit the objectivity of the measurements and generally slows down the time required to produce scientific data. Herein lies the need to implement image analysis software with artificial intelligence that can substitute the human operator. In this paper, we present a new method to study the growth rates of the plants of the Lemnaceae family based on the application of machine-learning procedures to digital image analysis. The method is compared to existing analogical and computer-operated procedures. The results showed that our method drastically reduces the time consumption of the human operator while retaining a high correlation in the growth rates measured with other procedures. As expected, machine-learning methods applied to digital image analysis can overcome the constraints of measuring growth rates of very small plants and might help duckweeds gain worldwide attention thanks to their strong nutritional qualities and biological plasticity