A study On Support Selection Mechanism In Tendrils of Cayratia Japonica

Organisms make decisions when they perceive cues of varying intensities. In case of climbing plants, the diameter of supports in contact (tree or stem) is an important cue for their growth as plants that coil around a support with large diameter are unable to maintain tensional forces required for continued attachment to the support. The negative association between the diameter and the climbing success has been reported since Darwin published his study on climbing plants. However, it is not known if a climbing plant makes a decision to avoid a support with larger diameter. Here, we tested this possibility by observing the coiling response of tendrils of Cayratia japonica to supports with different diameters. The coiling success of the tendrils was affected by the diameter of the support and the tendril lengths. We described the branching pattern of coiling response and demonstrated that the tendrils change their coiling shape depending on the support diameter and the tendril length. To understand the behavioural rules regulating the branching, we constructed a simple model with two assumptions on the tendril movement, (1) when the tendrils receive a contact stimulus, they begin to coil from around the contact point and (2) there is a minimum coiling angle at which the tendrils coil up, once the tendril starts coiling. Image analysis and 3D motion tracking technique revealed that the movement of the tendrils were consistent with the two assumptions of the model. The results suggested that the tendrils flexibly changed the coiling shapes depending on the support diameter and simple behavioural rules could regulate this diameter-dependent response.

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.

The features of xylem tracheary elements in some herbaceous members of the family Convolvulaceae Horan.

Numerous narrow xylem tracheary elements (tracheids and vessels) are present in liana stems, along with a few wide vessels that perform the main water-conducting function. This trait, known as “vessel dimorphism”, has been identified in studies on water-conducting tissue in autotrophic plants, including a large number of perennial climbing plants and a number of annual vines. Information is lacking on the presence of vessel dimorphism in parasitic plants of the lianescent habit. In this study, we performed a structural analysis of stems in the autotrophic herbaceous vines of Convolvulus arvensis L. and Calystegia sepium (L.) R. Br., as well as in the parasitic vines of Cuscuta monogyna Vahl, Cuscuta planiflora Ten., Cuscuta approximata Bab., and Cuscuta campestris Yunck., of the family of Convolvulaceae Horan. The xylem of C. arvensis and C. sepium contains a few wide conductive elements and many narrow ones. This feature is typical of autotrophic climbing plants. Only narrow tracheary elements are present in the xylem of the parasitic vines of the genus of Cuscuta L. (dodders). The total number of the tracheary elements is an order of magnitude less in the dodders than it is in the autotrophic vines. It is possible that the autotrophic ancestor of dodders lost the characteristic feature of the xylem of climbing plants, known as vessel dimorphism, during its transition to the parasitic lifestyle.

Assessment of the Particulate Matter Reduction Potential of Climbing Plants on Green Walls for Air Quality Management

Background and objective: To improve air quality, particulate matter (PM) can be reduced using green infrastructure. Therefore, in this study, we aimed to determine the particulate matter reduction potential of climbing plants used for green walls, an element of vertical green infrastructure. Methods: A sealed chamber with controlled environmental variables was used to assess the PM reduction level caused by climbing plants. PM concentration in the plant chamber was measured after two and four hours of PM exposure, and the reduction potential was assessed based on the leaf area. Results: Compared to the empty chamber (Control), the PM reduction speed per hour was higher in the plant chamber, which confirmed that climbing plants contribute to the reduction of PM in the air. The PM reduction speed immediately after exposure in the plant chamber was high, but this slowed over time. Additionally, PM has been continuously reduced in plants with large leaves. As a result of calculating the particulate matter reduction level based on leaf area, it was found that there was a difference by particle size. Actinidia arguta, Parthenocissus tricuspidata, Trachelospermum asiaticum, and Euonymus fortunei var. radicans showed a high reduction effect. The trichomes on the leaf surface of Trachelospermum asiaticum were found to affect PM reduction. Conclusion: PM adsorption on the leaf surface is an important factor in reducing its concentration. It was possible to compare different plants by quantifying the amount of PM reduction during a fixed time period. These results can be used as the basic data to select the plant species suitable for urban green walls in terms of PM reduction.

Distribution and diversity of climbing species in Papum Pare District of Arunachal Pradesh, India

An investigation on the taxonomic diversity of climbing plants occurring in Papum Pare District, Arunachal Pradesh, northeastern India was conducted. A total of 187 species distributed over 55 families and 117 genera were collected and identified from the various forest areas of the district. Apart from one gymnosperm and five pteridophytes, all species belong to the angiosperm group. Fabaceae, Cucurbitaceae, Convolvulaceae, Vitaceae, and Apocynaceae were found to be the most dominant. Piper, Dioscorea, Ipomoea, and Rubus were dominant at the genus level. The study also revealed that majority of the climbers adopted twining mechanisms (43.85%) to ascend their host. It was found that a majority of the species were distributed below 500m with a decrease in diversity with altitudinal increment. The diversity of species above 1,500m was very limited where only 23 species were reported. Habitat degradation because of rapid developmental activities with limitation of the supporting tree species was found to be a serious threat to climbing plants.

Are wounded-tree beetles living fossils? A new nosodendrid genus from Burmese amber with bilobed tarsi (Coleoptera: Nosodendridae)

Nosodendridae, the wounded-tree beetles, are a small polyphagan family with less than 100 described species placed into two extant and one fossil genera. Here we describe a new nosodendrid genus and species, Mesonosa scandens gen. et sp. nov., from mid-Cretaceous Burmese amber from northern Myanmar (ca. 99 Ma). The new genus differs from extant nosodendrids in its bilobed tarsomeres 2–4, as well as putatively plesiomorphic characters such as strongly protuberant compound eyes and relatively elongate prosternum. The distinctly lobed tarsi are a unique feature within Nosodendridae, and likely represent an adaptation for climbing plants. The discovery of a third wounded-tree beetle genus from the Mesozoic indicates that while their body plan remained relatively conserved since the Cretaceous, nosodendrids have been more ecomorphologically diverse in the geological past than the present day, and thus are an example of a true “living fossil” lineage.