Čeleď brukvovitých patří k největším rostlinným čeledím; zahrnuje 49 tribů, 321 rodů a 3 660 druhů. Zájem vědců o tuto rostlinnou skupinu vzrostl především díky ustanovení huseníčku rolního (Arabidopsis thaliana) modelovým druhem a sekvenování jeho genomu. To v r. 2000 odstartovalo mimo jiné bouřlivý rozvoj srovnávací fylogenomiky a cytogenomiky, včetně úspěšného zavedení metody malování chromozomů (chromosome painting) huseníčku a její aplikace na další zástupce brukvovitých (srovnávací malování chromozomů; comparative chromosome painting, CCP). Metoda CCP umožňuje studium chromozomové kolinearity, rozpoznání chromozomových přestaveb, porovnání struktury chromosomů nebo jejich částí mezi jednotlivými druhy a rekonstrukci struktury celých karyotypů. Brukvovité jsou jedinou rostlinnou čeledí, u níž je v tomto rozsahu metoda CCP použitelná. Srovnávací cytogenetické mapy brukvovitých tak představují zcela unikátní typ dat o evoluci rostlinných karyotypů a genomů., Whole-genome sequencing of the model plant Arabidopsis thaliana has stimulated a rapid development of comparative phylogenomics and cytogenomics, including the invention of chromosome painting in A. thaliana and comparative chromosome painting (CCP) in other species of the Brassicaceae (Cruciferae) family. This is the only plant family in which large-scale CCP is feasible. CCP provides unique insights into the karyotype and genome evolution in plants by comparing chromosome collinearity, identification of chromosome rearrangements, construction of comparative cytogenetic maps, and reconstruction of ancestral karyotype structures., and Terezie Mandáková.
The transfer of light energy from phycobilisomes (PBS) to photosystem II (PSII) reaction centers is vital for photosynthesis in cyanobacteria and red algae. To investigate the relationship between PBS and PSII and to optimize the energy transfer efficiency from PBS to PSII, isolation of the PBS-PSII supercomplex is necessary. SPC (sucrose/phosphate/citrate) is a conventional buffer for isolating PBS-PSII supercomplex in cyanobacteria. However, the energy transfer occurring in the supercomplex is poor. Here, we developed a new buffer named SGB by adding 1M glycinebetaine and additional sucrose to SPC buffer. Compared to SPC, the newly developed SGB buffer greatly enhanced the associated populations of PBS with thylakoid membranes and PSII and further improved the energy transfer efficiency from PBS to PSII reaction centers in cyanobacteria in vitro. Therefore, we conclude that SGB is an excellent buffer for isolating the PBS-PSII supercomplex and for enhancing the energy transfer efficiency from PBS to PSII reaction centers in cyanobacteria in vitro., L. P. Chen, Q. X. Wang, W. M. Ma., and Obsahuje bibliografii
We have developed a simple and an effective method for the isolation of photochemically active broken chloroplasts from conifer needles that can be applied for a wide variety of conifer species with needle-like leaves. The utilisation of this method in photosynthetic studies offers a possibility to examine the efficiency of almost any component of thylakoid electron-transport chain and to disclose information about individual parts of primary photosynthetic processes that would be otherwise difficult to obtain. Various aspects influencing the outcome of this procedure, including the amount of needles necessary for sufficient yields, the possible length and the conditions of their storage, the best method for their disruption, the composition and pH of isolation and storage buffers, the centrifugation sequence, etc., are discussed., D. Holá ... [et al.]., and Obsahuje bibliografii
a1_The aim of this work was to study the acclimation of photosynthesis in a boreal grass (Phalaris arundinacea L.) grown in controlled environment chambers under elevated temperature (ambient + 3.5°C) and CO2 (700 μmol mol-1) with varying soil water regimes. More specifically, we studied, during two development stages (early: heading; late: florescence completed), how the temperature response of light-saturated net photosynthetic rate
(Psat), maximum rate of ribulose-1,5-bisphosphate carboxylase/oxygenase activity (Vcmax) and potential rate of electron transport (Jmax) acclimatized to the changed environment. During the early growing period, we found a greater temperature-induced enhancement of Psat at higher measurement temperatures, which disappeared during the late stage. Under elevated growth temperature, Vcmax and Jmax at lower measurement temperatures (5-15°C) were lower than those under ambient growth temperature during the early period. When the measurements were done at 20-30°C, the situation was the opposite. During the late growing period, Vcmax and Jmax under elevated growth temperature were consistently lower across measurement temperatures. CO2 enrichment significantly increased Psat with higher intercellular CO2 compared to ambient CO2 treatment, however, elevated CO2 slightly decreased Vcmax and Jmax across measurement temperatures, probably due to down-regulation acclimation. For two growing periods, soil water availability affected the variation in photosynthesis and biochemical parameters much more than climatic treatment did. Over two growing periods, Vcmax and Jmax were on average 36.4 and 30.6%, respectively, lower with low water availability compared to high water availability across measurement temperatures. During the late growing period, elevated growth temperature further reduced the photosynthesis under low water availability., a2_Vcmax and Jmax declined along with the decrease in nitrogen content of leaves as growing period progressed, regardless of climatic treatment and water regime. We suggest that, for grass species, seasonal acclimation of the photosynthetic parameters under varying environmental conditions needed to be identified to fairly estimate the whole-life photosynthesis., Z.-M. Ge ... [et al.]., Obsahuje poznámky, and Obsahuje bibliografii
Agrolesnické systémy v tropických oblastech nabízejí možnost, jak zajistit trvale udržitelnou produkci na obdělávaných pozemcích, a často představují jediný zalesněný ekosystém v okolní odlesněné krajině. Tento článek se věnuje problematice agrolesnictví v tropech se zaměřením na kávové plantáže pěstované v Peru., Agroforestry systems present a way to keep sustainable production in cultivated areas, especially in the tropical zone. At the same time it is often the only forested ecosystem in otherwise deforested landscape. This article is about agroforestry in tropical areas, with the focus on coffee (Coffea) plantations in Peru., and Lenka Ehrenbergerová.
Leaf canopy plays a determining role influencing source-sink relations as any change in source activity (photosynthesis) affects sink metabolism. Defoliation (removal of leaves) influences growth and photosynthetic capacity of plants, remobilizes carbon and nitrogen reserves and accelerates sink metabolism, leading to improved source-sink relations. The response of plants to defoliation could be used to manipulate source-sink relations by removing lower and senescing leaves to obtain greatest photosynthetic capacity and efficient carbon and nitrogen metabolism under optimal and stressful environments. The present work enhances our current understanding on the physiological responses of plants to defoliation and elaborates how defoliation influences growth, photosynthetic capacity and source-sink relations under optimal and changing environmental conditions., N. Iqbal, A. Masood, and N. A. Khan., and Obsahuje bibliografii
At present, research activities on the role of orchard systems in sequestering atmospheric CO2 remain scarce. This paper aimed to contribute to assessing the carbon balance of a Mediterranean olive (Olea europea) orchard. The net ecosystem exchange, the ecosystem respiration and the gross primary production were computed for two consecutive years through eddy covariance, and the different biomass accumulation terms were also inferred in the same period through an inventorial method. The net carbon exchange ranged from 13.45 t(C) ha-1 year-1 to 11.60 t(C) ha-1 year-1. Very similar values [12.2 and 11.5 t(C) ha-1 year-1] were found with the direct carbon accumulation inventory. The intensive farming management (irrigation included) and the young age of the plants (12-16 years old), still in an active growing phase, led the olive plantation to be a higher carbon sink with respect to other evergreen orchards reported in the literature., M. Nardino ... [et al.]., and Obsahuje bibliografii
Botanická a mykologická nomenklatura je plná názvů převzatých z antické mytologie. Krása rostlin a hub přinesla do názvosloví mladé bohy a bohyně, motivem pro využití jmen byly také léčivé účinky nebo jedovatost, vzezření či místo výskytu rostlin a hub., Botanical and mycological nomenclature is full of names borrowed from ancient mythology. The beauty of plants and fungi brought young gods and goddesses into nomenclature. Another motive for using the names were the healing properties or toxicity, the appearance and the habitat of plants and fungi., and Tomáš Pavlík.
Apostasioideae jsou nejmenší, vývojově nejpůvodnější a současně nejméně prozkoumanou podčeledí vstavačovitých (Orchidaceae). Vyskytují se ve dvou rodech a 17 druzích v podrostu tropických lesů v jihovýchodní Asii. Od ostatních orchidejí se liší mj. specifickou květní morfologii a pylovými zrny nespojenými v brylky. Studium jaderného genomu ukázalo, že Apostasioideae mají jedny z nejmenších genomů mezi orchidejemi a jejich DNA je velice bohatá na adenin a thymin. Skupina je mimo svoji domovinu prakticky nepěstovatelná a chybí proto i ve velkých specializovaných sbírkách., Apostasioideae is the smallest, least specialized orchid subfamily, which is still largely unexplored. It encompasses 17 terrestrial species in two genera native to tropical rain forests of SE Asia. They differ from other orchids in their unique floral morphology and pollen shed in monads. Our flow cytometric analyses showed that apostasioids possess very small genomes with a considerable proportion of adenine and thymine. The lack of information stems at least partly from their extremely difficult cultivation outside native areas., and Jana Jersáková, Jan Ponert, Pavel Trávníček, Jan Suda.