Relations in the Size Variation of Plant Organs: a Case Study of Staghorn Sumac Leaves and Longleaf Pine Cone Scales

Plants automatically control the size variations in organs to achieve efficient exploitation of resources. However, it is unclear whether the scaling relationships of plant organs share a similar character for different individuals under varied micro-conditions (e.g., light and soil water). We conducted a case study of the lengths of staghorn sumac leaves and longleaf pine cone scales to test the relationships. Our results indicated that although there were size variations, there existed power laws of frequency in the lengths of staghorn sumac leaves and longleaf pine cone scales. The exponents differed but were positively correlated with the minimum length of leaves or cone scales. Taylor’s Law existed in the lengths of cone scales and some tree leaves, and scale break was observed. This study provides new information on scaling relationships and self-organization in the patterns of tree parts arrangement. Taylor’s Law may be used to detect minor changes in the growth regime.

Discovery of coprolites in an Early Permian fern mesophyll

Plants and arthropods interact with each other and constitute an important part of the modern terrestrial ecosystem (Schoonhoven et al., 2005). Historically, fossil records of plant-arthropod interactions have been well documented in Paleozoic terrestrial ecosystems, which were evidenced by large coprolites containing various plant fragments (e.g., Salter et al., 2012), small larvae and coprolites remained in plant organs (e.g., Feng et al., 2017), and diverse functional feeding groups discovered on plant stems, rachises, roots, leaves and fertile organs (e.g., Liu et al., 2020).

The annotation and analysis of complex 3D plant organs using 3DCoordX

A fundamental question in biology concerns how molecular and cellular processes become integrated during morphogenesis. In plants, characterization of 3D digital representations of organs at single-cell resolution represents a promising approach to addressing this problem. A major challenge is to provide organ-centric spatial context to cells of an organ. We developed several general rules for the annotation of cell position and embodied them in 3DCoordX, a user-interactive computer toolbox implemented in the open-source software MorphoGraphX. It enables rapid spatial annotation of cells even in highly curved biological shapes. With the help of 3DCoordX we obtained new insight by analyzing cellular growth patterns in organs of several species. For example, the data indicated the presence of a basal cell proliferation zone in the ovule primordium of Arabidopsis thaliana. Proof-of-concept analyses suggested a preferential increase in cell length associated with neck elongation in the archegonium of Marchantia polymorpha and variations in cell volume linked to central morphogenetic features of a trap of the carnivorous plant Utricularia gibba. Our work demonstrates the broad applicability of the developed strategies as they provide organ-centric spatial context to cellular features in plant organs of diverse shape complexity.

Root-To-Shoot Signaling for the Coding of Support Thickness in Pea Plants

Plants characterized by a soft or weak steam, such as climbing plants, need to find a potential support (e.g., wooden trunk) to reach greater light exposure. Since Darwin’s research on climbing plants, several studies on their searching and attachment behaviors have demonstrated their unique ability to process different support features to modulate their movements accordingly. Nevertheless, the strategies underlying this ability are yet to be uncovered. The present research tries to fill this gap by investigating how the interaction between above- (i.e., stem, tendril, …) and belowground (i.e., the root system) plant organs influence the kinematics of the approach-to-grasp movement. With three-dimensional (3D) kinematical analysis, we characterized the movement of pea plants (Pisum sativum L.) towards a support with different thicknesses above and belowground (i.e., thin below, thick aboveground, or the opposite). As a control condition, the plants were presented to supports with the same thickness below- and aboveground (i.e., either entirely thin or thick). The results suggest an integration between the information from below- and aboveground for driving the reach-to-grasp behavior of the aerial plant organs. Information about the support conveyed by the root system seems particularly important to fulfil the end-goal of the movement.

​Effects of Foliar Application of Nano-Se On Photosynthetic Characteristics and Se Accumulation in Paeonia Ostii

Background Selenium is an essential micronutrient in human metabolism. However, the Se level in foods is far below the standards due to the fact that it is deficient in two thirds of arable soils. Therefore, consuming Se-enriched plant products which convert inorganic Se into organic Se might be a safe and effective way to supplement Se for the human body. Paeonia ostii is a unique medicinal and edible plant in China, and also a new special woody oil crop. It serves as a perfect mediator for Se biofortification. In this report the effects of nano-Se foliar application on photosynthetic parameters, physiological characteristics and Se-enrichment effect in various plant organs of P. ostii cultivar Feng Dan were investigated in randomized complete block design experiments with different doses of spray in Se-deficient soils.Results By contrast to the control, nano-Se sprays enhanced net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, and chlorophyll content of Feng Dan. The content of soluble sugar, soluble protein, proline and activities of superoxide dismutase and peroxidase were increased while malondialdehyde content was significantly reduced. The stimulatory effect at concentrations of 6.00 and 8.25 g·hm-2 was the best in this study. nano-Se application significantly increased the Se content in all organs of Fengdan except the root compared to the control, and Se contents in various organs were increased paralleled with the increase of concentrations applied, and ordered as follows under suitable concentration, Testa > leaf > kernel > stem > root.ConclusionsThe above results show that nano-Se sprays at concentrations of 6.00-8.25 g·hm-2 stimulated the growth of Feng Dan and achieved the best Se-enrichment effect in this study. It also proved that the Se biofortification effect depends on its dosage applied and types of plant organs. These results provide guidance on Se enrichment of horticultural crops.

Plant-like hooked miniature machines for on-leaf sensing and delivery

New sustainable strategies for preserving plants are crucial for tackling environmental challenges. Bioinspired soft and miniature machines have the potential to operate in forests and agricultural fields by adapting their morphology to plant organs like leaves. However, applications on leaf surfaces are limited due to the fragility and heterogeneity of leaves, and harsh outdoor conditions. Here, we exploit the strong shear-dependent leaf-attachment of the hook-climber Galium aparine to create miniature systems that enable precision anchoring to leaf tissues via multifunctional microhooks. We first study the anchoring forces of the microhooks and then fabricate a soft wireless multiparameter sensor to monitor the leaf proximity and degradable hooks for in-plant molecular delivery to the vascular tissues of the leaves. In addition, we use a soft robotic proof-of-concept demonstrator to highlight how our hooks enable ratchet-like motion on leaves. This research showcases opportunities for specifically designing multifunctional machines for targeted applications in plant ecosystems.

STUDY OF CARBOHYDRATE COMPOSITION OF BLUE BLUE (POLEMONIUM CAERULEUM L.)

Polemonium coeruleum (Greek valerian) is a very promising plant for study. Despite the data available in the literature concerning the analysis of the main group of compounds of Greek valerian (triterpene saponins), the remaining groups of the metabolome were practically not affected for study. The aim of the study was to study the carbohydrates of grass and rhizomes with Greek valerians roots. The objects of the study were a sample of grass and rhizomes with Greek valerian roots. The content of the sum of polysaccharides and free sugars in terms of glucose was determined in accordance with the corresponding pharmacopoeial articles of the State Pharmacopoeia of the Russian Federation XIV ed. The profile and quantitative content of simple reducing sugars was studied by capillary electrophoresis. This work was the first to study the sum of free polysaccharides and simple sugars in grass and rhizomes with Greek valerian roots in comparison with the use of modern physicochemical methods. It was revealed that the content of the sum of free polysaccharides and the sum of simple sugars in terms of glucose in the aboveground part of Greek valerian is higher than in the underground one. It was shown that the composition of free simple sugars between plant organs is different and is represented by fructose and sucrose.