Govindjee at 80: more than 50 years of free energy for photosynthesis

Revelations on photosystem II, thermoluminescence, and artificial photosynthesis: a retrospective of Govindjee from fundamentals to applications

Photosynthesis, as one of the most important chemical reactions, has powered our planet for over four billion years on a massive scale. This review summarizes and highlights the major contributions of Govindjee from fundamentals to applications in photosynthesis. His research included primary photochemistry measurements, in the picosecond time scale, in both Photosystem I and II and electron transport leading to NADP reduction, using two light reactions. He was the first to suggest the existence of P680, the reaction center of PSII, and to prove that it was not an artefact of Chlorophyll a fluorescence. For most photobiologists, Govindjee is best known for successfully exploiting Chlorophyll a fluorescence to understand the various steps in photosynthesis as well as to predict plant productivity. His contribution in resolving the controversy on minimum number of quanta in favor of 8-12 vs 3-4, needed for the evolution of one molecule of oxygen, is a milestone in the area of photosynthesis research. Furthermore, together with Don DeVault, he is the first to provide the correct theory of thermoluminescence in photosynthetic systems. His research productivity is very high: ~ 600 published articles and total citations above 27,000 with an h-index of 82. He is a recipient of numerous awards and honors including a 2022: Lifetime Achievement Award of the International Society of Photosynthesis Research. We hope that the retrospective of Govindjee described in this work will inspire and stimulate the readers to continue probing the photosynthetic apparatuses with new discoveries and breakthroughs.

Global Trends of Usage of Chlorophyll Fluorescence and Projections for the Next Decade

Chlorophyll fluorescence is the most widely used set of techniques to probe photosynthesis and plant stress. Its great versatility has given rise to different routine methods to study plants and algae. The three main technical platforms are pulse amplitude modulation (PAM), fast rise of chlorophyll fluorescence, and fast repetition rate. Solar-induced fluorescence (SIF) has also gained interest in the last few years. Works have compared their advantages and their underlying theory, with many arguments advanced as to which method is the most accurate and useful. To date, no data has assessed the exact magnitude of popularity and influence for each methodology. In this work, we have taken the bibliometrics of the past decade for each of the four platforms, have evaluated the public scientific opinion toward each method, and possibly identified a geographical bias. We used various metrics to assess influence and popularity for the four routine platforms compared in this study and found that, overall, PAM currently has the highest values, although the more recent SIF has increased in popularity rapidly during the last decade. This indicates that PAM is currently one of the fundamental tools in chlorophyll fluorescence.

Microalgal hydrogen production: prospects of an essential technology for a clean and sustainable energy economy

Modern energy production is required to undergo a dramatic transformation. It will have to replace fossil fuel use by a sustainable and clean energy economy while meeting the growing world energy needs. This review analyzes the current energy sector, available energy sources, and energy conversion technologies. Solar energy is the only energy source with the potential to fully replace fossil fuels, and hydrogen is a crucial energy carrier for ensuring energy availability across the globe. The importance of photosynthetic hydrogen production for a solar-powered hydrogen economy is highlighted and the development and potential of this technology are discussed. Much successful research for improved photosynthetic hydrogen production under laboratory conditions has been reported, and attempts are underway to develop upscale systems. We suggest that a process of integrating these achievements into one system to strive for efficient sustainable energy conversion is already justified. Pursuing this goal may lead to a mature technology for industrial deployment.

Frederick Yi-Tung Cho (1939-2011) : His PhD days in Biophysics, the Photosynthesis Lab, and his patents in engineering physics

We present here a Tribute to Frederick Yi-Tung Cho (1939-2011), an innovative and ingenious biophysicist and an entrepreneur. He was one of the 4 earliest PhD students [see: Cederstrand (1965)-Carl Nelson Cederstrand; coadvisor: Eugene Rabinowitch; Papageorgiou (1968)-George C. Papageorgiou (coauthor of this paper); and Munday (1968)-John C. Munday Jr. (also a coauthor of this paper)] of one of us (Govindjee) in Biophysics at the University of Illinois at Urbana-Champaign (UIUC) during the late 1960s (1963-1968). Fred was best known, in the photosynthesis circle for his pioneering work on low temperature (down to liquid helium temperature, 4 K) absorption and fluorescence spectroscopy of photosynthetic systems; he showed temperature independence of excitation energy transfer from (i) chlorophyll (Chl) b to Chl a and (ii) from Chl a 670 to Chl a 678; and temperature dependence of energy transfer from the phycobilins to Chl a and from Chl a 678 to its suggested trap. After doing research in biophysics of photosynthesis, Fred shifted to do research in solid-state physics/engineering in the Government Electronics Division (Group) of the Motorola Company, Scottsdale, Arizona, from where he published research papers in that area and had several patents granted. We focus mainly on his days at the UIUC in context of the laboratory in which he worked. We also list some of his papers and most of his patents in engineering physics. His friends and colleagues have correctly described him as an innovator and an ingenious scientist of the highest order. On the personal side, he was a very easy-going and amiable individual.

Prasanna K. Mohanty (1934-2013): a great photosynthetiker and a wonderful human being who touched the hearts of many

Prasanna K. Mohanty, a great scientist, a great teacher and above all a great human being, left us more than a year ago (on March 9, 2013). He was a pioneer in the field of photosynthesis research; his contributions are many and wide-ranging. In the words of Jack Myers, he would be a "photosynthetiker" par excellence. He remained deeply engaged with research almost to the end of his life; we believe that generations of researchers still to come will benefit from his thorough and enormous work. We present here his life and some of his contributions to the field of Photosynthesis Research. The response to this tribute was overwhelming and we have included most of the tributes, which we received from all over the world. Prasanna Mohanty was a pioneer in the field of "Light Regulation of Photosynthesis", a loving and dedicated teacher-unpretentious, idealistic, and an honest human being.

Govindjee, an institution, at his 80th (really 81st) birthday in Třeboň in October, 2013: a pictorial essay

Govindjee (one name only), who himself is an institution, has been recognized and honored by many in the past for he is a true ambassador of "Photosynthesis Research" to the World. He has been called "Mr. Photosynthesis", and compared to the Great Wall of China. To us in Třeboň, he has been a great research collaborator in our understanding of chlorophyll a fluorescence in algae and in cyanobacteria, and more than that a friend of the Czech "Photosynthesis" group, from the time of Ivan Šetlík (1928-2009) and of Zdeněk Šesták (1932-2008). Govindjee's 80th (really 81st) birthday was celebrated by the Institute of Microbiology, Laboratory of Photosynthesis, by toasting him with an appropriate drink of a suspension of green algae grown at the institute itself. After my presentation, on October 23, 2013, of Govindjee's contributions to photosynthesis, and his intimate association with the photosynthetikers (in Jack Myers's words) of the Czech Republic, Govindjee gave us his story of how he began research in photosynthesis in the late 1950s. This was followed by a talk on October 25 by him on "Photosynthesis: Stories of the Past." Everyone enjoyed his animated talk-it was full of life and enjoyment. Here, I present a brief pictorial essay on Govindjee at his 80th (really 81st) birthday in Třeboň during October 23-25, 2013.