A Comprehensive History of Tea from Prehistoric Times to the Present Day
George L. van Driem
The Botanical Emergence in Contemporary Art
Plant’s fixity, perceived passivity, and resilient silence have relegated the vegetal world to the cultural background of human civilization. However, the recent emergence of plants in the gallery space constitutes a wake-up-call to reappraise this relationship at a time of deep ecological and ontological crisis. Why Look at Plants? challenges readers’ pre-established notions through a diverse gathering of insights, stories, experiences, perspectives, and arguments encompassing multiple disciplines, media, and methodologies.
Anam Moosa, Ayaz Farzand, Shahbaz Talib Sahi and Sajid Aleem Khan
Being sessile organisms, plants are continuously challenged by phytopathogenic fungi, contributing the largest share in loss due to plant disease. Plants naturally possess a well-developed and programmed protein-based defense system, capable of producing antimicrobial cationic peptides to ward off pathogen attack. Numerous genes encoding antifungal proteins have been isolated, cloned, sequenced and transgenically expressed against multiple phytopathogenic fungi successfully. Genetic engineering technology has been widely utilized to produce transgenic plants with enhanced resistance against pathogens. Pathogenesis-related proteins (PR-proteins) is a group of the most important inducible defense-related antifungal proteins, including defensins, thionins, osomtin-like proteins, thaumatin-like proteins, chitinases, glucanases, oxalate oxidase or oxalate oxidase-like proteins and lipid transfer proteins. Transgenic plants have been developed by imparting the artificial expression of genes encoding antifungal PR-proteins. The expression of transgenes belonging to a single group of PR-proteins or synergistic action of transgenes from different groups has greatly uplifted the level of defense response in plants against fungi. Transgenic expression of antifungal PR-proteins has led to remarkably enhanced resistance in transgenic plants. In this review, we have summarized the role of PR-proteins in plant defense against fungi and 15 years of success achieved so far to generate a variety of transgenic plants resistant against fungi through overexpression of transgenes from different groups of PR-proteins.
Guangfu Zhang and Rui Yao
Spinescence (including spines, thorns, and prickles) plays an important role in defense from herbivores. To examine whether spinescence evolved at random or differently in various life forms, plant organs, and aquatic taxa at the level of families, we analyzed the characteristics of wild spinescent aquatic plant species in the Yangtze Delta, East China. There were 92 such species, belonging to 33 genera and 21 families out of 203 wild aquatic vascular macrophyte species. Reproductive structures (including flowers, seeds, fruits and appendages) were well defended in the majority of aquatic plants compared with vegetative organs, especially for emerged macrophytes, probably resulting from the selective pressure from herbivores. Overall, most of the aquatic plants (67 species, 62.0% of the total number of species) had spiny reproductive structures while the others (41 species, 38.0% of the total number of species) had spiny vegetative organs, mostly in leaves, and only a few had thorny or prickly stems. In terms of spinescent aquatic species, there were significant differences among various life forms. Emerged macrophytes had 63 species, accounting for 58.3% of the whole; furthermore, the majority of such species (i.e. 42) were spinescent in reproductive organs. In contrast, the number of spiny floating and submerged plant species was eight and 37, respectively. It is noted that some families had more spiny species than others, especially the Cyperaceae and Najadaceae, which mainly defended their reproductive organs. Therefore, like terrestrial flora, aquatic plants also evolved spinescence as a defense against herbivores.
Kiran S. Khandagale, Rahul L. Zanan and Altafhusain B. Nadaf
Rice (Oryza sativa L.) is one of the most important food crops. Various conventional and modern techniques have been employed for improvement in rice. RNA interference (RNAi) is one of the popular reverse genetic strategies being practiced among plant scientists due to its efficiency and specificity. Nowadays, new age-targeted genome editing tools such as transcription activator-like effectors nucleases (TALEN) and clustered regularly interspaced palindromic repeats (CRISPR/Cas) are becoming popular due to their ability of precise modification of genome sequence and regulation of gene expression patterns in a site-specific manner. Here, we reviewed the utility of RNAi, TALEN and CRISPR/Cas in various aspects of rice improvement such as plant architecture, plant development, biotic and abiotic stress tolerance and qualitative improvement. A comparison of RNAi and targeted genome editing methods will provide some insights for researchers working on improvement of rice.
Nirit Bernstein, Mollie Sacks, Piny Snir and Rivka Rosenberg
Ca deficiencies induce a range of physiological disorders in plants. The disorders typically appear in young growing tissues that are characterized by high demand for Ca and restricted Ca supply due to low transpiration. In this study, we examined the effect of supplementing Ca by foliar spray and through the irrigation solution to Anemone coronaria plants, in order to evaluate if flower abortions and leaf damages that appear in the production fields are related to Ca deficiencies. With the goal to develop a preventive nutritional regime, four Ca treatments were evaluated. The supplemented Ca was applied with the fertigation solution in the concentrations of 60 or 110 ppm Ca; with the 60 ppm application an additional application of Ca by foliar application was tested in concentrations of 3 g/l Ca or 6 g/l Ca, as Ca(NO3)2. The plants were cultivated in a net-house, in soilless culture (Tuff) beds. Application of 110 ppm Ca compared to 60 ppm with the fertilizing solution increased the concentration of Ca in the leaf tissue, resulting in an increase in the quantity and quality of the flowers. Calcium supply by foliar spray, at both 3 g/l or 6 g/l Ca(NO3)2 caused leaf necrosis and did not improve yield production. Application of 110 ppm Ca reduced the concentrations of Mn, Cl and Na in the leaves. Application of Ca in the irrigation solution, or by foliar spray, did not reduce the percentage of non-marketable flowers. The identified lower concentrations of Ca in damaged compared to non-damaged leaves on the flower stem suggests that the damages to the flowers and the leaves is related to local deficiencies of Ca.
Namita Bhutani, Rajat Maheshwari, Monika Negi and Pooja Suneja
Endophytic bacteria isolated from nodules of Vigna radiata were screened for indole acetic acid (IAA) production. Three isolates MBN3, MJHN1 and MJHN10, molecularly identified as Bacillus aryabhattai (MF693121.1), B. megaterium (MF693120.1) and B. cereus (MF693119.1) were producing significantly high amount of IAA. Production parameters viz. L-tryptophan concentration, incubation time, carbon and nitrogen sources were optimized. The study revealed the presence of trp-dependent pathway for IAA production in the isolates. All of them gave maximum production with yeast extract as nitrogen source but variation in preference for carbon sources was observed. The invitro application of bacterial isolates on plant roots resulted in increase in root length as well as number of lateral roots. These results confirm the occurrence of Bacillus as predominant non-rhizobial endophytic genera in summer season crop and its potential as plant root growth promoter.
Rotem Fratkin Segman, Zvy Dubinsky and David Iluz
Since the Industrial Revolution, increasing atmospheric CO2 has been causing a rise in the concentration of carbon dioxide dissolved in seawater. This process results in seawater acidification, which has a major impact on the physical and chemical parameters of the oceans, consequently affecting the numerous calcifying organisms in the marine environment. Calcifying organisms secrete calcium carbonate in their inner or outer skeleton and include plankton (e.g. coccolithophores and foraminifera), corals, mussels and some of the macroalgae. Calcifying macroalgae make a critical contribution to the structure and function of marine ecosystems in several coastal biotas, providing food and shelter to diverse organisms. The present review summarizes the current information about the brown alga Padina sp. and its ecophysiology, focusing on the environmental control of the calcification process; suggests possible benefits that seaweeds may derive from their calcium carbonate cover, and discuss different future Intergovernmental Panel on Climate Change scenarios of ocean acidification and their likely impact on calcifying algae and on the ecosystems in which they are a key component.
Masuma Hakim, Dipika Rathod, Devanshi A. Trivedi, Jitendriya Panigrahi, Saikat Gantait and Illa C. Patel
Our study developed a HPTLC fingerprint profile of alkaloids and glycosides obtained from the methanol extracts of four different plant parts of Terminalia arjuna, T. bellerica and T. chebula, trees with cardio-protective values. The multiple qualitative phytochemical analyses of water, acetone, petroleum ether and methanol extracts from all the plant parts of Terminalia spp. detected the presence of alkaloids and glycosides, wherein the methanol extracts exhibited the presence of maximum alkaloids and glycosides. The chromatographic analysis of methanol extracts was carried out on silica gel 60F254HPTLC aluminium sheets with CAMAG Linomat 5 applicator. The plates were developed using ethyl acetate:toluene:formic acid (10:10:1; v/v/v) mobile phase. Alkaloids and glycosides were detected at 254 nm, 366 nm and 540 nm (after derivatization). These developed fingerprints would eventually be of great benefit in identifying or differentiating the alkaloids and glycosides in the form of marker compounds in the three Terminalia spp. mentioned.
Bernstein Nirit, Sara Gutman and Rosenberg Rivka
Visual leaf damage symptoms affect plant and flower development. A variety of physiological leaf symptoms are induced by environmental and growing conditions, including light intensity during cultivation and the nutrition status of the leaves. In the present study, we studied effects of leaf age, leaf ionome, and shade factor during cultivation (20% and 47% shade – under shade nets), on the development of leaf disorders in two cultivars of Phlox paniculata. The leaf ionome of both cultivars changed with leaf age, and varied between cultivars. The percentage of shade applied during cultivation by shade nets, had a minor effect on the leaf ionome, and it did not affect the type and severity of the leaf disorders that developed on the plants, nor the stage of development of their appearance. The ionome of young leaves and mature leaves that were affected by a purple spotting disorder was similar to that of ‘healthy’-looking leaves, demonstrating that this disorder is not related to the nutritional status of the tissue. Our results further excluded leaf age, plant age, plant trimming and shade factor during cultivation (by shade nets) as inducers of the purple spots disorder. This study is first to explore the ionome of Phlox paniculata and in relation to leaf age, physiological leaf disorders and shade factor during cultivation.