scholarly journals Case not closed: the mystery of the origin of the carpel

EvoDevo ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Beatriz Gonçalves

AbstractThe carpel is a fascinating structure that plays a critical role in flowering plant reproduction and contributed greatly to the evolutionary success and diversification of flowering plants. The remarkable feature of the carpel is that it is a closed structure that envelopes the ovules and after fertilization develops into the fruit which protects, helps disperse, and supports seed development into a new plant. Nearly all plant-based foods are either derived from a flowering plant or are a direct product of the carpel. Given its importance it’s no surprise that plant and evolutionary biologists have been trying to explain the origin of the carpel for a long time. Before carpel evolution seeds were produced on open leaf-like structures that are exposed to the environment. When the carpel evolved in the stem lineage of flowering plants, seeds became protected within its closed structure. The evolutionary transition from that open precursor to the closed carpel remains one of the greatest mysteries of plant evolution. In recent years, we have begun to complete a picture of what the first carpels might have looked like. On the other hand, there are still many gaps in our understanding of what the precursor of the carpel looked like and what changes to its developmental mechanisms allowed for this evolutionary transition. This review aims to present an overview of existing theories of carpel evolution with a particular emphasis on those that account for the structures that preceded the carpel and/or present testable developmental hypotheses. In the second part insights from the development and evolution of diverse plant organs are gathered to build a developmental hypothesis for the evolutionary transition from a hypothesized laminar open structure to the closed structure of the carpel.

2020 ◽  
Vol 6 (50) ◽  
pp. eabc8895
Author(s):  
Yuzhou Zhang ◽  
Lesia Rodriguez ◽  
Lanxin Li ◽  
Xixi Zhang ◽  
Jiří Friml

Flowering plants display the highest diversity among plant species and have notably shaped terrestrial landscapes. Nonetheless, the evolutionary origin of their unprecedented morphological complexity remains largely an enigma. Here, we show that the coevolution of cis-regulatory and coding regions of PIN-FORMED (PIN) auxin transporters confined their expression to certain cell types and directed their subcellular localization to particular cell sides, which together enabled dynamic auxin gradients across tissues critical to the complex architecture of flowering plants. Extensive intraspecies and interspecies genetic complementation experiments with PINs from green alga up to flowering plant lineages showed that PIN genes underwent three subsequent, critical evolutionary innovations and thus acquired a triple function to regulate the development of three essential components of the flowering plant Arabidopsis: shoot/root, inflorescence, and floral organ. Our work highlights the critical role of functional innovations within the PIN gene family as essential prerequisites for the origin of flowering plants.


Author(s):  
Mahnoosh Hassankhani ◽  
Mehdi Alidadi ◽  
Ayyoob Sharifi ◽  
Abolghasem Azhdari

COVID-19 shocked cities around the world and revealed the vulnerability of urban lives and functions. Most cities experienced a catastrophic disturbance that has lasted for a long time. Planning plays a critical role in responding efficiently to this crisis and enabling rapid functional recovery in the post-disaster era. Cities that have implemented digitalization initiatives and programs are likely to have more capacity to react appropriately. Specifically, digitalized cities could ensure the well-being of their residents and maintain continuity of urban functions. This research aims to analyze the role of technology in crisis management in the last two decades and provide appropriate policy recommendations for dealing with the COVID-19 pandemic. Systematic literature review and subjective content analysis are employed to investigate the effects of technology on community well-being and making cities more resilient in past crises. This study shows that different technology-driven policies and actions enable crisis management, enhance community well-being, and increase urban resilience. Technology has enhanced coping and recovery capacities by increasing participation and social connectedness, enhancing physical and mental health and maintaining the functionality of education and economic systems. These have been achieved through various solutions and technologies such as social media, telehealth, tracking and monitoring systems, sensors and locational applications, teleworking systems, etc. These solutions and technologies have also been used during the COVID-19 pandemic to enhance community well-being and sustain urban functions. However, technology deployment might have adverse effects such as social exclusion, digital divide, privacy and confidentiality violation, political bias and misinformation dissemination, and inefficient remote working and education. It is suggested that to mitigate these side effects, policymakers should liberate the process of digitalization, increase the accessibility to digital services, and enhance digital literacy.


Author(s):  
Stefan A. Rensing ◽  
Dolf Weijers

AbstractThe seeds of flowering plants are sexually produced propagules that ensure dispersal and resilience of the next generation. Seeds harbor embryos, three dimensional structures that are often miniatures of the adult plant in terms of general structure and primordial organs. In addition, embryos contain the meristems that give rise to post-embryonically generated structures. However common, flowering plant embryos are an evolutionary derived state. Flowering plants are part of a much larger group of embryo-bearing plants, aptly termed Embryophyta. A key question is what evolutionary trajectory led to the emergence of flowering plant embryos. In this opinion, we deconstruct the flowering plant embryo and describe the current state of knowledge of embryos in other plant lineages. While we are far yet from understanding the ancestral state of plant embryogenesis, we argue what current knowledge may suggest and how the knowledge gaps may be closed.


2014 ◽  
Vol 369 (1648) ◽  
pp. 20130348 ◽  
Author(s):  
Lena C. Hileman

A striking aspect of flowering plant (angiosperm) diversity is variation in flower symmetry. From an ancestral form of radial symmetry (polysymmetry, actinomorphy), multiple evolutionary transitions have contributed to instances of non-radial forms, including bilateral symmetry (monosymmetry, zygomorphy) and asymmetry. Advances in flowering plant molecular phylogenetic research and studies of character evolution as well as detailed flower developmental genetic studies in a few model species (e.g. Antirrhinum majus , snapdragon) have provided a foundation for deep insights into flower symmetry evolution. From phylogenetic studies, we have a better understanding of where during flowering plant diversification transitions from radial to bilateral flower symmetry (and back to radial symmetry) have occurred. From developmental studies, we know that a genetic programme largely dependent on the functional action of the CYCLOIDEA gene is necessary for differentiation along the snapdragon dorsoventral flower axis. Bringing these two lines of inquiry together has provided surprising insights into both the parallel recruitment of a CYC -dependent developmental programme during independent transitions to bilateral flower symmetry, and the modifications to this programme in transitions back to radial flower symmetry, during flowering plant evolution.


2018 ◽  
Vol 374 (1763) ◽  
pp. 20170394 ◽  
Author(s):  
Daniel S. Park ◽  
Ian Breckheimer ◽  
Alex C. Williams ◽  
Edith Law ◽  
Aaron M. Ellison ◽  
...  

Phenology is a key biological trait that can determine an organism's survival and provides one of the clearest indicators of the effects of recent climatic change. Long time-series observations of plant phenology collected at continental scales could clarify latitudinal and regional patterns of plant responses and illuminate drivers of that variation, but few such datasets exist. Here, we use the web tool CrowdCurio to crowdsource phenological data from over 7000 herbarium specimens representing 30 diverse flowering plant species distributed across the eastern United States. Our results, spanning 120 years and generated from over 2000 crowdsourcers, illustrate numerous aspects of continental-scale plant reproductive phenology. First, they support prior studies that found plant reproductive phenology significantly advances in response to warming, especially for early-flowering species. Second, they reveal that fruiting in populations from warmer, lower latitudes is significantly more phenologically sensitive to temperature than that for populations from colder, higher-latitude regions. Last, we found that variation in phenological sensitivities to climate within species between regions was of similar magnitude to variation between species. Overall, our results suggest that phenological responses to anthropogenic climate change will be heterogeneous within communities and across regions, with large amounts of regional variability driven by local adaptation, phenotypic plasticity and differences in species assemblages. As millions of imaged herbarium specimens become available online, they will play an increasingly critical role in revealing large-scale patterns within assemblages and across continents that ultimately can improve forecasts of the impacts of climatic change on the structure and function of ecosystems. This article is part of the theme issue ‘Biological collections for understanding biodiversity in the Anthropocene’.


2016 ◽  
Vol 8 (1) ◽  
pp. 42 ◽  
Author(s):  
Bridget O. Bobadoye ◽  
Paul N. Ndegwa ◽  
Lucy Irungu ◽  
Fombong Ayuka ◽  
Robert Kajobe

A vast majority of insects visit flowers for food, generally termed as floral rewards. Detailed insights on flowering phenology of plants could give a hint of habitat status and the extent to which such landscapes could support insect pollinators to render both direct and indirect ecosystem services. This study monitored flowering plants which could potentially provide both pollen and nectar sources to four African meliponine bee species (Apidae: Meliponini) naturally occurring in six diverse habitat gradients of the eastern arc mountains (Taita hills) of Kenya. Blooming sequences of identified flowering plants overlapped across seasons with approximately 80 different plant species belonging to 34 families recorded, with the highest proportions from Fabaceae and Asteraceae families dominating flowering plants that were visited (67% of the visits).  A flowering calendar is presented to indicate the phenological pattern of all identified floral resources.  Hypotrigona gribodoi being the most abundant species had the highest visitation rates on plants belonging to Fabaceae and Asteraceae families, followed by Meliponula ferruginea (black), Plebeina hildebrandti and Hypotrigona ruspolii. This indicates that such fragile habitat could invariably sustain nutritional requirements essential for the survival of insect pollinators such as native meliponine bee species, though bee abundance at flowers did not significantly correlate to food availability (expressed by flowering plant richness).


2021 ◽  
Author(s):  
William J. Baker ◽  
Paul Bailey ◽  
Vanessa Barber ◽  
Abigail Barker ◽  
Sidonie Bellot ◽  
...  

AbstractThe tree of life is the fundamental biological roadmap for navigating the evolution and properties of life on Earth, and yet remains largely unknown. Even angiosperms (flowering plants) are fraught with data gaps, despite their critical role in sustaining terrestrial life. Today, high-throughput sequencing promises to significantly deepen our understanding of evolutionary relationships. Here, we describe a comprehensive phylogenomic platform for exploring the angiosperm tree of life, comprising a set of open tools and data based on the 353 nuclear genes targeted by the universal Angiosperms353 sequence capture probes. This paper (i) documents our methods, (ii) describes our first data release and (iii) presents a novel open data portal, the Kew Tree of Life Explorer (https://treeoflife.kew.org). We aim to generate novel target sequence capture data for all genera of flowering plants, exploiting natural history collections such as herbarium specimens, and augment it with mined public data. Our first data release, described here, is the most extensive nuclear phylogenomic dataset for angiosperms to date, comprising 3,099 samples validated by DNA barcode and phylogenetic tests, representing all 64 orders, 404 families (96%) and 2,333 genera (17%). Using the multi-species coalescent, we inferred a “first pass” angiosperm tree of life from the data, which totalled 824,878 sequences, 489,086,049 base pairs, and 532,260 alignment columns. The tree is strongly supported and highly congruent with existing taxonomy, while challenging numerous hypothesized relationships among orders and placing many genera for the first time. The validated dataset, species tree and all intermediates are openly accessible via the Kew Tree of Life Explorer. This major milestone towards a complete tree of life for all flowering plant species opens doors to a highly integrated future for angiosperm phylogenomics through the systematic sequencing of standardised nuclear markers. Our approach has the potential to serve as a much-needed bridge between the growing movement to sequence the genomes of all life on Earth and the vast phylogenomic potential of the world’s natural history collections.


The article describes the morphological characteristics and biochemical parameters of a very little studied wild species Linum pubescens (downy flax). This representative of the genus Linum naturally grows in the eastern Mediterranean: Palestine, Syria, Lebanon, Israel, Turkey, Iraq, Greece, Cyprus, Albania. There are brief references to it in the description of the flora of these regions. In Israel, on natural populations of L. pubescens, studies of dimorphic heterostyly, anatomical features of the flower, mechanisms of pollination and incompatibility were carried out. However, other signs, including economically valuable ones, are not described in him. We were the first to study the species ex-situ in a field bank. It was found that in the arid conditions of the southeastern Steppe of Ukraine L. pubescens has a one-year development cycle, a height of 30 cm, 1.2 flowering stems, a bright pink flower with a diameter of 25 mm, a small slightly elongated box with a diameter of 2.7 mm, weight 1000 seeds is 0.6 g, and the leaf area is 218.9 mm2. Plants bloom in mid-July- September. Taking into account the rather large size, the bright color of the flower and the flowering period, we believe that the L. pubescens species has prospects of use as an ornamental flowering plant. In the resulting artificial population of L. pubescens, dimorphic heterostyly is clearly traced. Long and short pest morphs are clearly identified. L. pubescens seeds contain 24% protein and 35% oil. The fatty acid composition of the oil belongs to the "linum-type", like most other types of flax. With a low content of saturated acids (palmitic 6.7% and stearic 2.8%) and a significant predominance of unsaturated acids, especially linolenic up to 64%. It was revealed that this species has a dense non-cracking capsule. This trait is unusual for other flax varieties. Most annual and perennial species are characterized by moderate to severe cracking. Cultivated flax has a non-cracking boll, but not a hard one that breaks easily. It was found that less organic matter and more ash elements accumulate in the capsules and seeds of L. pubescens than in other species of the genus Linum. Probably, this feature, together with non-cracking, helps to better preserve fruits in difficult natural conditions and preserves seed germination for a long time. According to A.A. Zhuchenko, plant genetic resources are divided into six groups. At this stage, L. pubescen is classified as a wild weed relative. It was proposed to include L. pubescens in breeding work to create ornamental varieties in order to transfer it to the improved germplasm group in the future.


2016 ◽  
Vol 23 (2) ◽  
pp. 89-102
Author(s):  
Kuldeep Negi ◽  
Vandana Tiwari ◽  
Puran Mehta ◽  
Rajni Rawat ◽  
Saraswati Ojha ◽  
...  

Uttarakhand is a store house of plant genetic resources of several crop groups including ornamentals and seasonal flowering plant species. A wide range of seasonal flowering plants are being grown in the region because of its various and favourable agro-geo climatic zones. Ornamental plant enhances aesthetic value of our environment. There are 8 developmental blocks and 1082 villages in district Nainital of Uttarakhand. Nainital district, is a part of Kumaun region of Uttarakhand. It lies between 29?0.1' to 29?36' 21'' N latitude and 78?50' 53'' to 80?06' E longitude. More than 7.62 lakh population reside in 4064 km2 of geographical area of district Nainital. The district falls under sub-tropical to temperate zones. During the course of field survey (2013-2015), we came across wide range of seasonal flowering plants mostly belong to exotic origin being grown in the home gardens of natives of the region situated in different agro-ecological niches. The present study highlighted a total of 150 seasonal flowering plants with 120 genera belonging to 50 families. These were arranged alphabetically with botanical names followed by vernacular and trade name, family, origin or native place, nature, season with appropriate remarks of variation in shape, size and colour, method of propagation with economic status.


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