Introduction pages, Notulae Scientia Biologicae 14(3), 2022

Notulae Scientia Biologicae (http://www.notulaebiologicae.ro), Issue 3, Volume 14, 2022: The papers published in this issue represent interesting novelties in different topics of life science. Among the exciting research or reviews, we invite readers to find news about: Micropropagation and potential of bioactive compounds of saffron (Crocus sativus L.) for nutrition and health;Anatomical, physiological, biochemical and molecular responses of Eucalyptus spp. under water deficit conditions and characteristics of Tunisian arid species;Escherichia coli infection, a negative prognostic factor on the evolution of patients with surgical diseases;Biological characteristics and mortality in patients with diabetes and COVID-19;The influence of Staphylococcus infections on the evolution of hospitalized patients: The experience of the surgical department of IRGH Cluj-Napoca;Parquetina nigrescens leaf infusion: a food-based approach for the management of diet-induced iron deficiency in weanling rats;Evaluation of the effects of calabash chalk on the haematological profile of Wistar rats;Inhibitory potential of rutin on lipopolysaccharide-induced toxicity and inflammatory response of raw U937 cells and macrophages;Hypoglycemic and in vitro antioxidant activities of Stereospermum kunthianum stem bark hydromethanol extract;Polyploidization and speciation: patterns of natural hybridization and gene flow in basil (Ocimum spp.);Increasing liana biomass and carbon stocks in tropical dry evergreen forests of southern India.

Sanitation progress slows to a crawl amid pandemic

Speed read COVID-19 upped demand for water, sanitation and hygiene facilities But progress has been slow, before and since the pandemic began Data collection on WASH access is key to gaining ground, say experts Progress towards universal access to handwashing facilities has slowed in communities from Latin America to Sub-Saharan Africa amid the pandemic, data analysis reveals. According to the UN children’s agency UNICEF, 82 per cent of Brazilians had access to safe water sources in 2015, increasing slightly to 86 per cent in 2020. “The public water companies installed pipe systems and donated tanker trucks to the poorest communities, installed laundries for the street population and negotiated the water billing debt. [...]the increase in water consumption has been detrimental for some communities: in Algeria, water consumption increased with the rise in the number of COVID-19 cases, creating a major water deficit.

Microclimate control to increase productivity and nutritional quality of leafy vegetables in a cost-effective manner

Food security is one of the key global challenges in this century. In Singapore, our research team has been using novel aeroponic technology to produce fresh vegetables since 1997. Aeroponic systems allow for year-round production of not only tropical, but also sub-tropical and temperate fresh vegetables, by simply cooling the roots suspended in aeroponic systems while the aerial parts grow under tropical ambient environments. It has also been used to investigate the impacts of root-zone CO2 on vegetables by enriching root-zone CO2 while their aerial portions were subjected to constant atmospheric CO2. To compensate for the lack of available land, Singapore also needs to develop a farming system that can increase productivity per unit land area by many-fold. Over the past 10 years, my research team has established a commercially viable LED integrated vertical aeroponic farming system to grow different leafy vegetables under different LED spectra, intensities, and durations in the tropical greenhouse. The results demonstrate that it is possible to increase shoot production and rate of shoot production of leafy vegetables by increasing light intensity and extending the photoperiod under effective LED lighting. Furthermore, temperate vegetable crops such as lettuce were able to acclimate to high light intensity under supplementary LED lights to natural sunlight in the greenhouse. Supplementary LED lightings promote both leaf initiation and expansion with increased photo synthetic pigments, higher Cyt b6f and Rubisco protein contents on a per area basis and thus improve photosynthetic capacity and enhance productivity. Plants sense and respond to changes in their immediate environments (microclimate), manipulating the root zone temperature (RZT) and water supply will impact not only their growth and development but also their nutritional quality. Our on-going research aims to investigate if the nutritional quality of leafy vegetables could be improved under suboptimal RZT and mild water deficit through deficit irrigation. If substantial energy and water savings in urban farming can be achieved without substantial yield penalty but with higher nutritional quality, the amount of water and energy saved can bring substantial benefits to society.

Mycorrhizal Fungi Inoculation Improves Capparis spinosa’s Yield, Nutrient Uptake and Photosynthetic Efficiency under Water Deficit

Agricultural yields are under constant jeopardy as climate change and abiotic pressures spread worldwide. Using rhizospheric microbes as biostimulants/biofertilizers is one of the best ways to improve agro-agriculture in the face of these things. The purpose of this experiment was to investigate whether a native arbuscular mycorrhizal fungi inoculum (AMF-complex) might improve caper (Capparis spinosa) seedlings’ nutritional status, their morphological/growth performance and photosynthetic efficiency under water-deficit stress (WDS). Thus, caper plantlets inoculated with or without an AMF complex (+AMF and −AMF, respectively) were grown under three gradually increasing WDS regimes, i.e., 75, 50 and 25% of field capacity (FC). Overall, measurements of morphological traits, biomass production and nutrient uptake (particularly P, K+, Mg2+, Fe2+ and Zn2+) showed that mycorrhizal fungi inoculation increased these variables significantly, notably in moderate and severe WDS conditions. The increased WDS levels reduced the photochemical efficiency indices (Fv/Fm and Fv/Fo) in −AMF plants, while AMF-complex application significantly augmented these parameters. Furthermore, the photosynthetic pigments content was substantially higher in +AMF seedlings than −AMF controls at all the WDS levels. Favorably, at 25% FC, AMF-colonized plants produce approximately twice as many carotenoids as non-colonized ones. In conclusion, AMF inoculation seems to be a powerful eco-engineering strategy for improving the caper seedling growth rate and drought tolerance in harsh environments.

Interactive Effects of Drought and Saline Aerosol Stress on Morphological and Physiological Characteristics of Two Ornamental Shrub Species

Effects of drought and aerosol stresses were studied in a factorial experiment based on a Randomized Complete Design with triplicates on two ornamental shrubs. Treatments consisted of four levels of water container (40%, 30%, 20%, and 10% of water volumetric content of the substrate) and, after 30 days from experiment onset, three aerosol treatments (distilled water and 50% and 100% salt sea water concentrations). The trial was contextually replicated on two species: Callistemon citrinus (Curtis) Skeels and Viburnum tinus L. ‘Lucidum’. In both species, increasing drought stress negatively affected dry biomass, leaf area, net photosynthesis, chlorophyll a fluorescence, and relative water content. The added saline aerosol stress induced a further physiological water deficit in plants of both species, with more emphasis on Callistemon. The interaction between the two stress conditions was found to be additive for almost all the physiological parameters, resulting in enhanced damage on plants under stress combination. Total biomass, for effect of combined stresses, ranged from 120.1 to 86.4 g plant−1 in Callistemon and from 122.3 to 94.6 g plant−1 in Viburnum. The net photosynthesis in Callistemon declined by the 70% after 30 days in WC 10% and by the 45% and 53% in WC 20% and WC 10% respectively after 60 days. In Viburnum plants, since the first measurement (7 days), a decrease of net photosynthesis was observed for the more stressed treatments (WC 20% and WC 10%), by 57%. The overall data suggested that Viburnum was more tolerant compared the Callistemon under the experimental conditions studied.