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 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]

PhotosynQ at Feed the Future Legume Innovation Lab (LIL) Conference in Burkina Faso August 13-18, 2017

Following the PhotosynQ Workshop (see Dan’s post), we had moved to the LIL conference site at Laico Ouaga 2000, a high security hotel/conference venue outside of Ouagadougou city.  “Feed the Future” is a program funded by USAID under the US government’s Global Hunger and Food Security Initiative.  This program has been engaging many universities, institutions and private organizations in the US, Africa and Central/South America to improve the quality and management of legume, and contributing to the well-beings of local people. Michigan State University (http://legumelab.msu.edu/) is one of the leading institutions contributing researches and new technologies to the world.

One of the designated official languages being French, we had a simultaneous translation through headphone at this conference. The last time when I had to use French in daily basis was almost 20 years ago. Listening to the scientific talks was manageable, but my speaking ability was quite embarrassing. Another challenge was internet connectivity. As Dan mentioned, we had to manage the workshop with almost no internet connection. We were hoping to have a better connection at this best hotel in Burkina Faso, but unfortunately, it seemed the system could not handle a large traffic at once. The conference participants expressed that they had never experienced this in the past anywhere in Africa. It seems it was an isolated incidence, but we came up with some better solutions for the future.

  PhotosynQ booth (From right: Dan, Frank and Atsuko)

 Presentation by Dr. Irvin Widders, Director of Legume Innovation Lab, MSU. PhotosynQ was mentioned as one of the highlights of the ‘Feed the Future’ program.

At the last LIL conference held at Livingston, Zambia, Dave Kramer and Dan TerAvest presented the PhotosynQ project using MultispeQ Beta. This year in Burkina Faso, not only the people from Kramer Lab (Dave, Dan, Donghee Hoh, Isaac Osei-Bonsu and me), but also our PhotosynQ collaborators (Dr. Isaac Dramadri in Uganda, Dr. James Kelly with Dr. Jesse Traub and Dr. Wayne Loescher of MSU, and Dr. Kelvin Kamfwa of U of Zambia) presented more detailed and sophisticated data showing the correlations among photosynthesis, plant responses and gene expressions. It was very encouraging for us to see more people started thinking that the PhotosynQ platform and hand-held devices are useful and practical to the broad applications.

We are very excited about the new challenges, collaborations and long-lasting friendships. And we all hope to see you again!