Bahtijor Rasulov

Bahtijor Rasulov
University of Tartu · Institute of Molecular and Cell Biology

Doctor of sciences

About

40
Publications
7,648
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,591
Citations
Citations since 2016
11 Research Items
736 Citations
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
Introduction
Skills and Expertise

Publications

Publications (40)
Chapter
Isoprene is the most abundant non-methane hydrocarbon emitted to the atmosphere and a target of biotechnology as a source of biofuels or chemical feedstock. Measurements of the amount of isoprene or the rate of production of isoprene are important for atmospheric chemistry, evaluating biotechnology processes, and can provide information on the capa...
Article
Full-text available
Leaf isoprene emission rate, I, decreases with increasing atmospheric CO2 concentration with major implications for global change. There is a significant interspecific variability in [CO2]-responsiveness of I, but the extent of this variation is unknown and its reasons are not understood. We hypothesized that the magnitude of emission reduction ref...
Article
Full-text available
Treatment by volatile plant hormone methyl jasmonate (MeJA) leads to release of methanol and volatiles of lipoxygenase pathway (LOX volatiles) in a dose-dependent manner, but how the dose dependence is affected by stomatal openness is poorly known. We studied the rapid (0–60 min after treatment) response of stomatal conductance (Gs), net assimilati...
Article
Full-text available
Natural vegetation is predicted to suffer from extreme heat events as a result of global warming. In this study, we focused on the immediate response to heat stress. Photosynthesis and volatile emissions were measured in the leaves of tobacco (Nicotiana tabacum cv. Wisconsin 38) after exposure to heat shock treatments between 46 °C and 55 °C. Expos...
Article
Full-text available
During exposure to direct sunlight, leaf temperature increases rapidly and can reach values well above air temperature in temperate forest understories, especially when transpiration is limited due to drought stress, but the physiological effects of such high-temperature events are imperfectly understood. To gain insight into leaf temperature chang...
Article
Isoprene and other plastidial isoprenoids are produced primarily from recently assimilated photosynthates via the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. However, when environmental conditions limit photosynthesis, a fraction of carbon for MEP pathway can come from extrachloroplastic sources. The flow of extrachloroplastic carbon depends...
Article
Optimization between photosynthetic carbon assimilation and stomatal water loss is the key in order to breed crops for future climate. We analyzed stomatal conductance (gs), CO 2 assimilation rate (Anet), fungal diseases, grain yield and yield components of seven European malting barley genotypes treated with fungicides alone or together with biost...
Article
Full-text available
Guard cells shrink and close stomatal pores when air humidity decreases (i.e. when the difference between the vapor pressures of leaf and atmosphere [VPD] increases). The role of abscisic acid (ABA) in VPD-induced stomatal closure has been studied using ABA-related mutants that respond to VPD in some studies and not in others. The importance of ABA...
Article
Full-text available
Isoprene is synthesized via chloroplastic 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathway and its synthesis is directly related to photosynthesis, except under high CO2 concentration when the rate of photosynthesis increases, but isoprene emission decreases. Suppression of MEP/DOXP pathway activity by high CO2...
Article
Full-text available
Plant isoprene emissions respond to light and temperature similarly to photosynthesis, but CO2-dependencies of isoprene emission and photosynthesis are profoundly different with photosynthesis increasing and isoprene emissions decreasing with increasing CO2 concentration due to reasons not yet understood. We studied isoprene emission, net assimilat...
Article
Recently, a feedback inhibition of chloroplastic 1-deoxy-D-xylulose 5-phosphate/2-C-methyl-D-erythritol 4-phosphate pathway (DXP/MEP) of isoprenoid synthesis by end-products dimethylallyl diphosphate (DMADP) and isopentenyl diphosphate (IDP) was postulated, but the extent to which DMADP and IDP can build up is not known. We used bisphosphonate inhi...
Article
Full-text available
Acclimation of foliage to growth temperature involves both structural and physiological modifications, but the relative importance of these two mechanisms of acclimation is poorly known, especially for isoprene emission responses. We grew hybrid aspen (Populus tremula x P. tremuloides) under control (day/night temperature of 25/20 °C) and high temp...
Article
Full-text available
In growing leaves, lack of isoprene synthase is considered responsible for delayed isoprene emission, but competition for dimethylallyl diphosphate (DMADP), the substrate for both isoprene synthesis and prenyltransferase reactions in photosynthetic pigment and phytohormone synthesis, can also play a role. We used a kinetic approach based on postill...
Article
Full-text available
Effects of elevated atmospheric [CO(2) ] on plant isoprene emissions are controversial. Relying on leaf-scale measurements, most models simulating isoprene emissions in future higher [CO(2) ] atmospheres suggest reduced emission fluxes. However, combined effects of elevated [CO(2) ] on leaf area growth, net assimilation and isoprene emission rates...
Article
Full-text available
Controversial evidence of CO 2-responsiveness of isoprene emission has been reported in the literature with the response ranging from inhibition to enhancement, but the reasons for such differences are not understood. We studied isoprene emission characteristics of hybrid aspen (Populus tremula x P. tremuloides) grown under ambient (380 μmol mol -1...
Article
Full-text available
Changes in leaf sugar concentrations are a possible mechanism of short-term adaptation to temperature changes, with natural fluctuations in sugar concentrations in the field expected to modify the heat sensitivity of respiration. We studied temperature-response curves of leaf dark respiration in the temperate tree Populus tremula (L.) in relation t...
Article
Full-text available
After darkening, isoprene emission continues for 20 to 30 min following biphasic kinetics. The initial dark release of isoprene (postillumination emission), for 200 to 300 s, occurs mainly at the expense of its immediate substrate, dimethylallyldiphosphate (DMADP), but the origin and controls of the secondary burst of isoprene release (dark-induced...
Article
Full-text available
The responses of isoprene emission rate to temperature are characterized by complex time-dependent behaviors that are currently not entirely understood. To gain insight into the temperature dependencies of isoprene emission, we studied steady-state and transient responses of isoprene emission from hybrid aspen (Populus tremula × Populus tremuloides...
Article
Full-text available
Photosynthesis rate (A(n)) becomes unstable above a threshold temperature, and the recovery upon return to low temperature varies because of reasons not fully understood. We investigated responses of A(n), dark respiration and chlorophyll fluorescence to supraoptimal temperatures of varying duration and kinetics in Phaseolus vulgaris asking whether...
Article
Full-text available
Leaf isoprene emission scales positively with light intensity, is inhibited by high carbon dioxide (CO(2)) concentrations, and may be enhanced or inhibited by low oxygen (O(2)) concentrations, but the mechanisms of environmental regulation of isoprene emission are still not fully understood. Emission controls by isoprene synthase, availability of c...
Article
Full-text available
The control of foliar isoprene emission is shared between the activity of isoprene synthase, the terminal enzyme catalyzing isoprene formation from dimethylallyldiphosphate (DMADP), and the pool size of DMADP. Due to limited in vivo information of isoprene synthase kinetic characteristics and DMADP pool sizes, the relative importance of these contr...
Conference Paper
Full-text available
Recent investigations showed, that BVOC (biogenic volatile organic compounds) emissions, especially in the case of isoprene, are influenced by atmospheric CO 2 lev-els. Doubling the ambient CO 2 concentration leads to a drop in emission potential up to 50% in poplar seedlings. A biochemical regulation scheme of this behavior was recently proposed b...
Chapter
Full-text available
Rubisco content and its in vivo activity (kcat), as well as PSI content were measured in leaves of sunflower, tobacco, potato and birch. The biological variation of k cat was wide, ranging from 1 to 6 s−1 at 22.5°C. Plotting kcat against (Rubisco sites/PSI) resulted in a reciprocally decreasing relationship. The data show that carbamylated Rubisco...
Article
Full-text available
The oxidation kinetics under far-red light (FRL) of photosystem I (PSI) high potential donors P700, plastocyanin (PC), and cytochrome f (Cyt f) were investigated in sunflower leaves with the help of a new high-sensitivity photometer at 810 nm. The slopes of the 810 nm signal were measured immediately before and after FRL was turned on or off. The s...
Article
Full-text available
To follow stomatal responses to ozone (O3) in different Arabidopsis lines, we constructed a rapid-response O3 exposure/gas-exchange measurement device consisting of eight through-flow whole-rosette cuvettes. To separate rosette from roots and growth substrate, plant is grown through an agar-filled hole in a polished glass plate fixed on the pot. Fo...
Article
Full-text available
Sunflower (Helianthus annuus L.) and tobacco (Nicotiana tabacum L.) were grown in the laboratory and leaves were taken from field-grown birch trees (Betula pendula Roth). Chlorophyll fluorescence, CO2 uptake and O2 evolution were measured and electron transport rates were calculated, JC from the CO2 uptake rate considering ribulose-1,5-bisphosphate...
Article
Full-text available
The present study was performed to investigate the adjustment of the constituents of the light and dark reactions of photosynthesis to the natural growth irradiance in the leaves of an overstorey species, Betula pendula Roth, a subcanopy species Tilia cordata P. Mill., and a herb Solidago virgaurea L. growing in a natural plant community in Järvsel...
Article
Full-text available
The present study was performed to investigate the adjustment of the rate parameters of the light and dark reactions of photosynthesis to the natural growth light in leaves of an overstorey species, Betula pendula Roth, a subcanopy species, Tilia cordata P. Mill., and a herb, Solidago virgaurea L., growing in a natural plant community in Järvselja,...
Article
Full-text available
We describe a method of reductive titration of photosystem I (PSI) density in leaves by generating a known amount of electrons (e-) in photosystem II (PSII) and measuring the resulting change in optical signal as these electrons arrive at pre-oxidized PSI. The method complements a recently published method of oxidative titration of PSI donor side e...
Article
The global modelling of photosynthesis is based on exact knowledge of the leaf photosynthetic machinery. The capacities of partial reactions of leaf photosynthesis develop at different rates, but it is not clear how the development of photoreactions and the Calvin cycle are co-ordinated. We investigated the development of foliar photosynthesis in t...
Article
Full-text available
Two silver birch (Betula pendula Roth) clones K1659 and V5952 were grown in open-top chambers over 3 years (age 7–9 years). The treatments were increased CO2 concentration (+CO2, 72 Pa), increased O3 concentration (+O3, 2 × ambient O3 with seasonal AOT40 up to 28 p.p.m. h) and in combination (+CO2 + O3). Thirty-seven photosynthetic parameters were...
Article
Full-text available
By recording leaf transmittance at 820 nm and quantifying the photon flux density of far red light (FRL) absorbed by long-wavelength chlorophylls of Photosystem I (PS I), the oxidation kinetics of electron carriers on the PS I donor side was mathematically analyzed in sunflower (Helianthus annuus L.), tobacco (Nicotiana tabacum L.) and birch (Betul...
Article
Full-text available
Photosynthesis is a complex process whose rate is affected by many biochemical and biophysical factors. Fortunately, it is possible to determine, or at least estimate, many of the most important parameters using a combination of optical methods and gas transient analyses. We describe here a computer-operated routine that has been developed to make...
Article
Carbon dioxide uptake and fluorescence parameters were measured in sunflower (Helianthus annuus L.) leaves at different temperatures up to 45°C. In the dark, steady-state fluorescence F increased with temperature but part of it could be reversed by far-red light (F0). Pulse-saturated fluorescence Fm decreased and approached F at high temperature. I...
Article
Full-text available
Sunflower (Helianthus annuus L.), cotton (Gossypium hirsutum L.), tobacco (Nicotiana tabacum L.), sorghum (Sorghum bicolor Moench.), amaranth (Amaranthus cruentus L.), and cytochrome b6f complex-deficient transgenic tobacco leaves were used to test the response of plants exposed to differnt light intensities and CO2 concentrations before and after...
Article
Full-text available
Sunflower and cotton plants were grown in growth boxes at 460 �mol m-2 s-1. The mesophyll conductance in N2, the assimilatory charge (post-illumination CO2 uptake) and the CO2 capacity (the solubility of CO2 + HCO3- + CO32-) were measured at different temperatures. The mesophyll conductance had its maximum at 29-30°C in sunflower leaves and rapidly...
Article
Full-text available
The authors investigated the effect of oxygen on components of CO2 exchange and parameters of CO2 assimilation in cotton leaves at constant leaf temperature (34°C), saturating light intensity (33 mW cm-2), and low CO2 concentration (C a = 100 ul l l-1. Changes of oxygen concentration in the atmosphere from 1 to 21% do not affect the rate carboxylat...

Network

Cited By

Projects

Project (1)
Project
This is a European Research Council (ERC) funded project with the major aim of understanding how plant volatiles induced under stress conditions alter the future Earth climate. Most research on plant volatiles has concentrated on constitutive emissions that are emitted in some specialized species. We test the hypothesis that plant volatile emissions have been vastly underestimated because of stress volatiles that can be emitted from any plant species.