Nano-Fe (Magnetic-Fe) and Se Foliar Application Tranquilize the Salinity Adverse-Effects on Satureja Mutica Fisch and Satureia Spicigera (C. Koch) Boiss

Background: The secondary metabolites from savory species are widely used in food and pharmaceutical industries. Salt accumulation in the growing medium adversely affects the growth and yield of plants. The hyper-availability of Na+ and Cl- triggers nutrient imbalances, leading to secondary ionic stress. Under salinity exposure, the reactive oxygen species (ROS) over-generation drives oxidative stress in cells. Moreover, when facing environmental stress factors; the availability of essential nutrients and especially micro-elements strongly declines. Foliar application of micro-nutrients principally as nano-form is a promising strategy in meeting the nutritional demands of plants under stress environments with progressive nutrient shortages. Nano-materials and the supply of nutrients as foliar treatments meliorate the growth, biochemical reactions, and nutrient use efficiency of plants under salinity. The idea with the present experiment was to assay the effects of nano-Fe (magnetized-Fe) and selenium foliar application on the growth and some physiological responses of two Satureja species under saline-sodic conditions.Results: When studying the foliar application of Se and nano-Fe (0 and 3 mg L-1) on Satureja mutica and Satureia spicigera via two separate experiments, under normal no-saline conditions; the highest catalase activity was recorded in magnetized-Fe treated plants in both species. Independent effects of foliar application and plant species influenced total phenolics and Mg content of leaves. Foliar sprays reduced MDA content in plant tissue. In the second experiment, foliar applications were evaluated under salinity conditions. No-saline × Se and magnetized-Fe treated plants attained the highest data for aerial parts biomass in S. spicigera.Conclusion: The results demonstrated that salinity adversely influenced the growth and physiological responses, nevertheless, foliar spray with Se and magnetized-Fe partially ameliorated the salinity depression on Satureja species.

Understanding nutrient imbalances in maize (Zea mays L.) using the diagnosis and recommendation integrated system (DRIS) approach in the Maize belt of Nigeria

Low nutrient use efficiency in maize as a result of imbalanced nutrition has been reported to drastically reduce yield. We implemented a nutrient omission experiment to assess the effect of nutrient application on maize yield and nutritional balance. Maize ear leaves were analyzed for nutrients, to identify nutrient balance status using the Diagnostic and Recommendation Integrated System (DRIS) approach. Results indicated that omission of N or P resulted in highly imbalanced DRIS indices respectively, and significantly lower grain yield. A strong inverse relationship between K ear leaf content with DRIS index suggests that K application negatively increases K imbalance in many situations. Imbalances of Mg, Ca and Cu were more associated with higher yielding treatments. A Which-Won-Where result show that nutrient imbalances in the diagnosis were systematically frequent when N was omitted. All the diagnosed nutrients were imbalanced even under the highest yielding NPKZn treatment; indicating further opportunity for yield increase with more balanced nutrition. Balanced nutrition of maize in the maize belt of Nigeria should target application of varying rates of N, P, K, Mg, S and Zn, depending on the soil conditions. But, because of complexities of nutrient interactions during uptake, it is hardly possible to realize a balanced nutrition. However, differentiating the application of antagonistic nutrients into foliar or soil-based methods is recommended for a more balanced maize nutrition.

Multi-elemental isotope and analog tracer application to measure nutrient uptake and distribution in Malus domestica Borkh.

Plant nutrient uptake is critical to maintain an optimum balance between vegetative and reproductive growth and fruit quality. Nutrient imbalances, and more specifically the relationship of potassium, magnesium and nitrogen to calcium, can be critical for fruit quality in apple (Malus x domestica Borkh.). In perennial plants, it is difficult to conduct short-term experiments to measure plant uptake and distribution in response to either cultivar or treatment because of substantial preexisting nutrient pools already present. The use of isotopically labeled nitrogen, and nutrient analogs such as strontium and rubidium allow for the quantification of uptake and distribution that is often not possible with bulk mineral analysis. Here, the objective was to understand how scion genotype influences nutrient uptake and partitioning between aboveground and below ground parts of the tree. In this experiment, 10 atom% 15N, Strontium (Sr), and Rubidium (Rb) were applied to three different potted apple cultivars that were either treated with ABA 250 mg/L or 500 mg/L or an untreated control. After 70 days of growth, overall recovery rates of each tracer reflected the mobility of their nutrient analog. Strontium had an average tracer recovery rate of 3.9%, followed by 15N with 14.6% recovery and finally Rb with 15.1%. Independent of treatment, Gala significantly absorbed more tracer followed by Granny Smith and Honeycrisp for Rb and Sr but not 15N. These results have implications in understanding the association between aboveground factors like transpiration and nutrient uptake and distribution in apple.

Long-term Organic Production Systems in Northern Highbush Blueberry: Placing Weed Mat over Existing Organic Mulches and Changing to Nitrogen-only Fertilizer Sources Increased Yield

In long-lived organic blueberry production systems, nutrient imbalances caused by some fertilization and mulching practices can reduce plant growth and yield. The ability to balance nutrient levels and thus improve productivity over time was evaluated in a mature planting of ‘Duke’ and ‘Liberty’ that had been used to study different mulching practices [sawdust (9-cm deep), yard-debris compost (4-cm) topped with sawdust (5-cm), and weed mat] and various rates and sources of N fertilizer (feather meal or fish solubles, each applied initially at “low” or “high” rates of 29 and 57 kg·ha−1 N in 2007–08 and then increased incrementally as the planting matured to 73 and 140 kg·ha−1 N in 2013–16). In Winter 2016–17, existing weed mat was removed and replaced where it was present, and new weed mat was installed on top of any existing organic mulches, thus changing the mulch treatments to weed mat (over bare soil), weed mat over sawdust, and weed mat over compost + sawdust from 2017 to 2020. A hydrolyzed soy-protein–based fertilizer containing essentially only N was applied at a moderate rate (106 kg·ha−1 N) relative to prior treatments. Plants grown on flat and raised beds were evaluated separately. From 2016 to 2020, yield of ‘Duke’ and ‘Liberty’ increased by an average of 19% and 56%, respectively, on flat beds and 8% and 42%, respectively, on raised beds. On flat or raised beds, plants that had weed mat placed over the existing sawdust or compost + sawdust mulch had a greater increase in yield (averaging 41%) than those with weed mat alone (over bare soil; averaging 12%). Soil under weed mat alone continued to have the lowest organic matter content (averaging 3%) throughout the study. Prior fertilization source and rate had no impact on the increase in yield of ‘Duke’, whereas ‘Liberty’ plants previously fertilized with feather meal had a larger increase in yield through 2020 than those fertilized with fish solubles. Fertilizing with an intermediate rate of N from 2017 to 2020 increased yield regardless of whether plants received the low or high N rate from 2007 to 2016, confirming our previous conclusion that the low rate provided sufficient N. Soil K and leaf %K declined after discontinuing fertilization with fish solubles and use of yard-debris compost, likely a factor in yield improvement. However, there were still negative correlations between yield and leaf %K in multiple years. This study illustrated that changing mulch and fertility practices in established organic blueberry to mitigate prior applications of high K can improve plant performance, nutrient imbalances, and yield within a relatively short period of time.

Cape Verde Frontal Zone in summer 2017: lateral transports of mass, dissolved oxygen and inorganic nutrients

The circulation patterns in the confluence of the North Atlantic subtropical and tropical gyres delimited by the Cape Verde Front (CVF) were examined during a field cruise in summer 2017. We collected hydrographic data, dissolved oxygen (O2) and inorganic nutrients along the perimeter of a closed box embracing the Cape Verde Frontal Zone (CVFZ). The detailed spatial (horizontal and vertical) distribution of water masses, O2 and inorganic nutrients in the CVF was analyzed, allowing for the independent estimation of the transports of these properties in the subtropical and tropical domains down to 2000 m. Overall, at surface and central levels, a net westward transport of 3.76 Sv was observed, whereas at intermediate levels, a net 3 Sv transport northward was obtained. We observed O2 and inorganic nutrient imbalances in the domain consistent with O2 consumption and inorganic nutrient production by organic matter remineralization, resulting in a net transport of inorganic nutrients to the ocean interior by the circulation patterns.

Chromium (VI) Induced Physiological and Metabolic Responses in Vigna Mungo L. cv. BVN-3

The present study investigates the chromium (VI) induced phytoxicity and accumulation in the black gram (Vigna mungo L. cv. BVN-3) grown under refined sand pot culture. The phytotoxicity assessed with reference to growth behavior, water transport, metabolic alteration, yield, uptake and translocation of S, P, Fe and Cr under chromium (VI) stress. The black gram plants were treated with varied chromium (VI) at 0.00, 0.05, 0.10 and 0.25 mM concentration. After 5 d of Cr (VI) treatment, the foliar toxicity symptoms showed as loss of turgor and chlorosis of older leaves which also reflect in middle aged leaves later on at higher concentration of chromium (0.25 mM). At the later stage, chlorosis symptoms became critical and distorted to necrosis in patches with tapered lamina, thin tendrils and loosed coiling property. Cr (VI) induced toxicity observed on black gram as decreased growth and yield, impairment in photosynthesis activity, inhibition of metabolic and enzymatic activities and nutrient imbalances. Excess (0.25 mM) of Cr (VI) also caused a reduction in uptake and accumulation of iron in the leaves as compared to control (from 426.2 to 198.7 µg g-1 dw) with more uptake and accumulation of sulphur and phosphorus. Higher accumulation of Cr was recorded in the leaves (166.5 µg g-1 dw) followed by roots (123.4 µg g-1 dw) and stems (46.6 µg g-1 dw) at 0.25 mM after 29 d of treatment. Therefore, consumption of Cr containing black gram may have human health concern due to toxic Cr accumulation and nutrition imbalances.

A Microscopic and Metabolomic Description of Stip-affected Tissue in New Mexico Pod-type Pepper

Stip is a physiological disorder that affects certain pepper (Capsicum annuum) cultivars, most notably bell-pod types. It has been attributed in the literature to nutrient imbalances, temperature extremes, and/or other environmental stressors. Symptoms present as brown, black, and yellow ovoid-shaped necrotic lesions ≈0.5 to 1.2 cm long by 0.5 cm wide. Between 2014 and 2015, symptomatic and asymptomatic pods were harvested from 15 commercial farms in southern New Mexico. Fluorescent microscopy comparisons of harvested symptomatic tissue revealed a unique fluorescent signature and the absence of chlorophyll. A new spectral peak centered around 560 nm was observed in symptomatic tissue. High-performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry (GC-MS) analyses of these tissues detected significant differences in 13 metabolites, of which several have been associated with fruit maturation and/or senescence. This report represents the first combination of a detailed microscopic description and metabolite profile of field-grown symptomatic plants with this disorder.

A cross-sectional study of owner-reported health in Canadian and American cats fed meat- and plant-based diets

Background Cats, being obligate carnivores, have unique dietary requirements for nutrients most commonly found in dietary ingredients of animal origin. As such, feeding a diet devoid of animal-derived ingredients has been postulated as a possible cause of nutrient imbalances and adverse health outcomes. A small proportion of cat owners feed strictly plant-based diets to the cats in their care, yet the health and wellness of cats fed these diets has not been well documented. Results A total of 1325 questionnaires were complete enough for inclusion. The only exclusion criterion was failure to answer all questions. Most cats, 65% (667/1026), represented in the survey were fed a meat-based diet and 18.2% (187/1026) were fed a plant-based diet, with the rest fed either a combination of plant-based with meat-based (69/1026, 6.7%) or indeterminable (103/1026, 10%). Cat age ranged from 4 months to 23 years, with a median of 7 years, and was not associated with diet type. No differences in reported lifespan were detected between diet types. Fewer cats fed plant-based diets reported to have gastrointestinal and hepatic disorders. Cats fed plant-based diets were reported to have more ideal body condition scores than cats fed a meat-based diet. More owners of cats fed plant-based diets reported their cat to be in very good health. Conclusions Cat owner perception of the health and wellness of cats does not appear to be adversely affected by being fed a plant-based diet. Contrary to expectations, owners perceived no body system or disorder to be at particular risk when feeding a plant-based diet to cats. This study collected information from cat owners and is subject to bias, as well as methodological limitations. Further research is warranted to determine if these results are replicable in a prospective investigation.

Regulation of Root Nutrient Transporters by CIPK23: ‘One Kinase to Rule Them All’

Protein kinases constitute essential regulatory components in the majority of cellular processes in eukaryotic cells. The CBL-INTERACTING PROTEIN KINASE (CIPK) family of plant protein kinases functions in calcium (Ca2+)-related signaling pathways and is therefore involved in the response to a wide variety of signals in plants. By covalently linking phosphate groups to their target proteins, CIPKs regulate the activity of downstream targets, their localization, their stability and their ability to interact with other proteins. In Arabidopsis, the CIPK23 kinase has emerged as a major hub driving root responses to diverse environmental stresses, including drought, salinity and nutrient imbalances, such as potassium, nitrate and iron deficiencies, as well as ammonium, magnesium and non-iron metal toxicities. This review will chiefly report on the prominent roles of CIPK23 in the regulation of plant nutrient transporters and on the underlying molecular mechanisms. We will also discuss the different scenarios explaining how a single promiscuous kinase, such as CIPK23, may convey specific responses to a myriad of signals.