Biosynthesis of iron oxide nanoparticles from dates, characterization, and investigation of anticarcinogenic and antimicrobial properties

Nanomaterial synthesis using natural biological systems, especially plant-based green synthesis has evinced great excitement and interest. In this study, iron oxide nanomaterials were synthesized from three different varieties of date palms obtained from Srivilliputhur, Tamil Nadu, India. The extract of date palms reduced ferric chloride in solution and facilitated the formation of iron oxide nanomaterials. Phytochemical studies of the extracts obtained from all three varieties of date palms indicated the presence of phenols. The synthesized nanomaterials were characterized by UV-VIS spectroscopy, SEM, EDAX, XRD and FTIR methods. The ability of the synthesized nanomaterials to inhibit human microbial pathogens proliferation was tested in Staphylococcus sp. and Bacillus sp. by turbidity method and recorded the maximum antimicrobial property against Bacillus sp. in the iron nanomaterial synthesized from Sukhri date palm. The cytotoxic potential of the iron oxide nanomaterials was assessed against two human cancer cell lines (A-549 and MDA-MB-231) by MTT assay. The substantial cytotoxicity response was detected from the iron oxide nanomaterials made from Sukhri date palm.

Effects of Pollination Interventions, Plant Age and Source on Hormonal Patterns and Fruit Set of Date Palm (Phoenix dactylifera L.)

Date palm is widely propagated through conventional offshoots. It is also produced through a tissue culture technique due to the limited number of offshoots produced throughout the course of a palm’s life. Being dioecious, it is a cross-pollinated tree that can be naturally or artificially pollinated. Tissue-cultured plants often have abnormal epigenetic or genetic changes that affect specific phenotypic characteristics. The growth of parthenocarpic fruits in date palms is mostly induced by hormonal imbalances in certain tissues. The major hormones in parthenocarpic fruits are auxins (IAA), gibberellins (GA3), and abscisic acid (ABA). Parthenocarpic, or abnormal fruit development, is an undesirable trait for date palm growers since it drastically reduces farm income. The current study was therefore conducted over two seasons to confirm previous observations and included conventional offshoot-derived trees (CO) and tissue culture-derived ones (TC) of the cultivar Barhee. According to the observed ratio of the fruiting abnormalities, two date palm tree ages were selected, i.e., 6 and 13 years. Two pollination interventions were used: pollination of naturally open female spathes (NOP) and pollination of forced open female spathes (FOP). Plant hormones, IAA, GA3, and ABA were identified just before pollination and at specific intervals after pollination for up to 85 days. The ratio of the abnormal fruit set was identified 5 days after pollination. Significant differences were observed in hormonal levels between tree ages as well as between tree propagation sources. Young TC trees (6-year-old) had high abnormal fruit sets compared to CO date palm trees that were the same age. During the early fruit growth and development phases, CO date palms had much higher amounts of IAA and GA3 than TC date palms. However, ABA concentrations were surprisingly higher in the TC trees during the early fruit growth stages, while it immediately decreased after pollination in the CO date palms. The ratio of abnormal fruits was significantly reduced in the 13-year-old TC date palms, and no differences were observed compared to the CO ones. The levels of IAA, GA3, and ABA hormones in both young and old date palms derived through CO or TC followed similar patterns. The critical observations regarding the ABA pattern in the old TC date palms (13-year-old) gradually dropped after pollination, which was identical to the CO ones, whereas it was the opposite in the young 6-year-old TC date palm plants.

The Role of Canary Island Date Palms in Physical Amenity Provisioning for Urban Landscape Settings

Canary Island date palms (Phoenix canariensis) have been planted as a landscaping feature plant throughout warm, temperate, and subtropical climates. The physical amenity provisioning of this species (shade effects, microclimate amelioration, water usage, etc.) has so far not been systematically assessed. This paper reports on temperature and humidity measurements in both a suburban and a rural location in SE Australia. The study demonstrates the effects of the palm canopy as regulator of humidity and provider of shade and, thus, amenity values in urban landscape settings. Drawing on published energy savings and growth requirements of the plant, the paper argues that Canary Island date palms are landscaping plants suitable to ameliorate the microclimate in urban neighborhoods with varied socio-economic conditions.

Phylogeny and Mycotoxin Profile of Pathogenic Fusarium Species Isolated from Sudden Decline Syndrome and Leaf Wilt Symptoms on Date Palms (Phoenix dactylifera) in Tunisia

In 2017–2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusarium proliferatum, and at a much lesser extent, Fusarium brachygibbosum, Fusarium caatingaense, Fusarium clavum, Fusarium incarnatum, and Fusarium solani. Pathogenicity on the Deglet Nour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch’s postulates. Fusarium proliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F. brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusarium caatingaense, F. clavum, F. incarnatum produced only BEA. Fusarium solani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.

Inventory and Identification of Arthropods on Dates (Phoenix dactylifera L.)

Dates (Phoenix dactylifera L.) belong to the Arecaceae family of palms. Banjarbaru is one of the areas that started planting date palms in South Kalimantan. The community's knowledge of date pests still lacks. Therefore it becomes a problem for farmers. Before proper control is carried out, it is necessary to understand the types of pests first. Arthropod data on date palms at the Plantation and Livestock Service Office of South Kalimantan Province are not available. Hence, it is necessary to conduct inventory research and arthropod identification. This study aimed to determine the types of arthropods in date palms (P. dactylifera L.) in Banjarbaru. The method used was a survey method with purposive sampling carried out by collecting arthropods using swing nets, yellow sticky traps, and directly from four different locations. The field observations at four locations found 43 types of arthropods totaling 98 individuals. Twenty arthropods act as pests, 13 individuals as pollinators, and 10 individuals as predators. The arthropods were classified into ten orders and 27 families, with the largest number of individuals coming from the Lepidoptera order.

Rooting in the Desert: A Developmental Overview on Desert Plants

Plants, as sessile organisms, have evolved a remarkable developmental plasticity to cope with their changing environment. When growing in hostile desert conditions, plants have to grow and thrive in heat and drought. This review discusses how desert plants have adapted their root system architecture (RSA) to cope with scarce water availability and poor nutrient availability in the desert soil. First, we describe how some species can survive by developing deep tap roots to access the groundwater while others produce shallow roots to exploit the short rain seasons and unpredictable rainfalls. Then, we discuss how desert plants have evolved unique developmental programs like having determinate meristems in the case of cacti while forming a branched and compact root system that allows efficient water uptake during wet periods. The remote germination mechanism in date palms is another example of developmental adaptation to survive in the dry and hot desert surface. Date palms have also designed non-gravitropic secondary roots, termed pneumatophores, to maximize water and nutrient uptake. Next, we highlight the distinct anatomical features developed by desert species in response to drought like narrow vessels, high tissue suberization, and air spaces within the root cortex tissue. Finally, we discuss the beneficial impact of the microbiome in promoting root growth in desert conditions and how these characteristics can be exploited to engineer resilient crops with a greater ability to deal with salinity induced by irrigation and with the increasing drought caused by global warming.