New PhotosynQ Related Publication

Check out the new publication in Photosynthesis Research, using the MultispeQ and PhotosynQ Platform (10.1007/s11120-017-0449-9)

Faster photosynthetic induction in tobacco by expressing cyanobacterial flavodiiron proteins in chloroplasts

Rodrigo Gómez, Néstor Carrillo, María P. Morelli, Suresh Tula, Fahimeh Shahinnia, Mohammad-Reza Hajirezaei, Anabella F. Lodeyro

Plants grown in the field experience sharp changes in irradiation due to shading effects caused by clouds, other leaves, etc. The excess of absorbed light energy is dissipated by a number of mechanisms including cyclic electron transport, photorespiration, and Mehler-type reactions. This protection is essential for survival but decreases photosynthetic efficiency. All phototrophs except angiosperms harbor flavodiiron proteins (Flvs) which relieve the excess of excitation energy on the photosynthetic electron transport chain by reducing oxygen directly to water. Introduction of cyanobacterial Flv1/Flv3 in tobacco chloroplasts resulted in transgenic plants that showed similar photosynthetic performance under steady-state illumination, but displayed faster recovery of various photosynthetic parameters, including electron transport and non-photochemical quenching during dark–light transitions. They also kept the electron transport chain in a more oxidized state and enhanced the proton motive force of dark-adapted leaves. The results indicate that, by acting as electron sinks during light transitions, Flvs contribute to increase photosynthesis protection and efficiency under changing environmental conditions as those found by plants in the field.


More PhotosynQ related publications are available here

New PhotosynQ Related Publication

Check out the new publication in Plant Physiology, using the MultispeQ and PhotosynQ Platform (10.1104/pp.17.01624)

The Impacts of Phosphorus Deficiency on the Photosynthetic Electron Transport Chain

Andreas Carstensen, Andrei Herdean, Sidsel Birkelund Schmidt, Anurag Sharma, Cornelia Spetea, Mathias Pribil, Søren Husted

Phosphorus (P) is an essential macronutrient, and P deficiency limits plant productivity. Recent work showed that P deficiency affects electron transport to photosystem I (PSI), but the underlying mechanisms are unknown. Here, we present a comprehensive biological model describing how P deficiency disrupts the photosynthetic machinery and the electron transport chain through a series of sequential events in barley (Hordeum vulgare). P deficiency reduces the orthophosphate concentration in the chloroplast stroma to levels that inhibit ATP synthase activity. Consequently, protons accumulate in the thylakoids and cause lumen acidification, which inhibits linear electron flow. Limited plastoquinol oxidation retards electron transport to the cytochrome b6f complex, yet the electron transfer rate of PSI is increased under steady-state growth light and is limited under high-light conditions. Under P deficiency, the enhanced electron flow through PSI increases the levels of NADPH, whereas ATP production remains restricted and, hence, reduces CO2 fixation. In parallel, lumen acidification activates the energy-dependent quenching component of the nonphotochemical quenching mechanism and prevents the overexcitation of photosystem II and damage to the leaf tissue. Consequently, plants can be severely affected by P deficiency for weeks without displaying any visual leaf symptoms. All of the processes in the photosynthetic machinery influenced by P deficiency appear to be fully reversible and can be restored in less than 60 min after resupply of orthophosphate to the leaf tissue.


More PhotosynQ related publications are available here

New PhotosynQ Related Publication

 

Check out the new publication in the American Journal of Plant Sciences, using the MultispeQ and PhotosynQ Platform (10.4236/ajps.2017.89154)

Evaluation of Cowpea Genotypes for Resistance to Fusarium redolens in Uganda

Roy Wanjala Namasaka, Geoffrey Tusiime, Martin Orawu, Paul Gibson, Josiane Nyiramugisha, Richard Edema

Fusarium redolens, a virulent fungus which causes damping off, leaf yellowing, wilting and root rots has recently been devastating cowpea fields in Uganda. This study aimed at identifying cowpea genotypes that are resistant to Fusarium redolens. Therefore, ninety cowpea genotypes were evaluated two times against a highly virulent Fusarium redolens (isolate from Zombo in Paidha district) in the screen house in 2016. Genotype effect was highly significant (P < 0.001) for root rot severity. Based on the Index of Susceptibility (IS), three genotypes (Asontem, Dan1 LA and IT89KD-88) remained resistant (IS < 3.5) over the two screening periods, 72 moderately resistant (3.5 ≤ IS < 6.5) and 11 susceptible (IS ≥ 6.5). Resistance was found to be enhanced by presence of lateral roots above or at the ground level. Further results suggested a difference in genetic control of resistance to root rots and seed rots caused by Fusarium redolens. All the released varieties tested (SECOW 1 T, SECOW 2 W, SECOW 3 B, SECOW 4 W and SECOW 5 T) had moderate resistance to Fusarium redolens. Correlation analysis revealed root rot severity was strongly correlated to disease incidence (+0.64, P < 0.001), to proportion of plants with lateral roots (−0.56, P < 0.001), to amount of leaf chlorophyll (−0.53, P < 0.001) and to proportion of plants that died prematurely due to Fusarium redolens infection (+0.45, P < 0.001). No significant correlation was detected between root rot severity and proportion of plants that germinated. The established resistance could be exploited for improvement of farmer preferred cowpea varieties towards Fusarium redolens resistance in Uganda.


More PhotosynQ related publications are available here

New PhotosynQ Related Publication

Check out the new publication in Physiologia Planatarum, using the MultispeQ and PhotosynQ Platform (10.1111/ppl.12689)

Chlorophyll fluorescence imaging reveals genetic variation and loci for a photosynthetic trait in diploid potato

Aina E. Prinzenberg, Marcela Víquez-Zamora, Jeremy Harbinson, Pim Lindhout, Sjaak van Heusden

Physiology and genetics are tightly interrelated. Understanding the genetic basis of a physiological trait such as the quantum yield of the photosystem II, or photosynthetic responses to environmental changes will benefit the understanding of these processes. By means of chlorophyll fluorescence imaging “CF”, the quantum yield of photosystem II can be determined rapidly, precisely and non-invasively. In this article, the genetic control and variation in the steady-state quantum yield of PSII “ΦPSII” is analysed for diploid potato plants. Current progress in potato research and breeding is slow due to high levels of heterozygosity and complexity of tetraploid genetics. Diploid potatoes offer the possibility of overcoming this problem and advance research for one of the globally most important staple foods. With the help of a diploid genetic mapping population two genetic loci that were strongly associated with differences in ΦPSII were identified. This is a proof of principle that genetic analysis for ΦPSII can be done on potato. The effects of three different stress conditions that are important in potato cultivation were also tested: salt stress, low temperature and deficiency in the macronutrient phosphate. For the last two stresses, significant decreases in photosynthetic activity could be shown, revealing potential for stress detection with CF based tools. In general, our findings show the potential of high-throughput phenotyping for physiological research and breeding in potato.


More PhotosynQ related publications are available here

New PhotosynQ Related Publication

Check out the new publication in the American Journal of Plant Sciences, using the MultispeQ and PhotosynQ Platform (10.4236/ajps.2017.84050)

Response of Cowpea Genotypes to Drought Stress in Uganda

Saul Eric Mwale, Mildred Ochwo-Ssemakula, Kassim Sadik, Esther Achola, Valentor Okul, Paul Gibson, Richard Edema, Wales Singini, Patrick Rubaihayo

Moisture stress is a challenge to cowpea production in the drought prone areas of eastern and north eastern Uganda, with yield losses of up to 50% reported. Genotypes grown by farmers are not drought tolerant. This study was therefore, undertaken at Makerere University Agricultural Research Institute Kabanyolo to identify cowpea genotypes tolerant to drought. Thirty cowpea accessions comprising of Ugandan landraces and released varieties, Brazilian lines, Makerere University breeding lines, elite IITA germplasm and seven IITA drought tolerant lines as checks were screened for drought tolerance at vegetative and reproductive stages. The experiment was designed as a 2 × 37 factorial and laid out in a split-plot arrangement, 37 genotypes of cowpea at two soil moisture stress levels (T1, no stress and T2, severe stress) with all factorial combinations replicated two times in a screen house. The genotypes showed considerable variability in tolerance to drought. Genotypes were significantly different for chlorophyll content (P ≤ 0.01), efficiency of photosystem II (P ≤ 0.05), non-photochemical quenching (P ≤ 0.05), recovery (P ≤ 0.01), delayed leaf senescence (P ≤ 0.01), grain yield (P ≤ 0.01), 100 seed weight (P ≤ 0.05), number of pods per plant and number of seeds per pod (P ≤ 0.001). There was a highly significant positive correlation between chlorophyll content and efficiency of photosystem II (r = 0.75, P ≤ 0.001) implying that chlorophyll content and efficiency of photosystem II could be used as efficient reference indicators in the selection of drought tolerant genotypes. Genotypes SECOW 5T, SECOW 3B, SECOW 4W, WC 30 and MU 24 C gave relatively high yields under stress and no stress conditions, maintained above mean chlorophyll content, efficiency of photosystem II and had good recovery scores from stress and thus were tolerant to drought stress induced at both vegetative and reproductive stages.


More PhotosynQ related publications are available here

New PhotosynQ Related Publication

Check out the new publication in Photosynthesis Research, using the MultispeQ and PhotosynQ Platform (10.1007/s11120-017-0449-9)

Faster photosynthetic induction in tobacco by expressing cyanobacterial flavodiiron proteins in chloroplasts

Rodrigo GómezNéstor Carrillo, María P. Morelli, Suresh Tula, Fahimeh Shahinnia, Mohammad-Reza Hajirezaei, Anabella F. Lodeyro

Plants grown in the field experience sharp changes in irradiation due to shading effects caused by clouds, other leaves, etc. The excess of absorbed light energy is dissipated by a number of mechanisms including cyclic electron transport, photorespiration, and Mehler-type reactions. This protection is essential for survival but decreases photosynthetic efficiency. All phototrophs except angiosperms harbor flavodiiron proteins (Flvs) which relieve the excess of excitation energy on the photosynthetic electron transport chain by reducing oxygen directly to water. Introduction of cyanobacterial Flv1/Flv3 in tobacco chloroplasts resulted in transgenic plants that showed similar photosynthetic performance under steady-state illumination, but displayed faster recovery of various photosynthetic parameters, including electron transport and non-photochemical quenching during dark–light transitions. They also kept the electron transport chain in a more oxidized state and enhanced the proton motive force of dark-adapted leaves. The results indicate that, by acting as electron sinks during light transitions, Flvs contribute to increase photosynthesis protection and efficiency under changing environmental conditions as those found by plants in the field.


More PhotosynQ related publications are available here

Intelligent Information Technologies in Education and Science – Ukraine

 

On October 18, 2017, the Interdisciplinary Workshop on the dissemination of knowledge on “Intellectual Information Technologies in Education and Science” took place at the Faculty of Chemistry and Biology of the Ternopil National Pedagogical University (TNPU).

The co-organizers of this event were Andriy and Natalia Hertz, employees of the Department of General Biology and Methodology of Natural Sciences Teaching and the Department of Botany and Zoology (Faculty of Chemistry and Biology of TNPU).

According to the program, a demonstration of the possibilities of IT solutions in biological, educational and pedagogical research took place. 

In particular, the on-line PhotosynQ platform was presented as a web tool for an integrated assessment of the physiological state of plants. 

Information was disseminated on how the MultispeQ can measure, collect and analyze photosynthesis data in field and laboratory conditions.

The focus was on the openness and flexibility of the PhotosynQ platform and the development of educational tools through it, and more.

The students and faculty all wished to have the opportunity to work with MultispeQ and PhotosynQ and to evaluate the condition of plants for themselves.

More Info [English] | More Info [Original]