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Special Issue "Photosynthesis"

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Biochemistry".

Deadline for manuscript submissions: closed (31 October 2018).

Special Issue Editor

Assoc. Prof. Dr. Matteo Ballottari
E-Mail Website
Guest Editor
Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134 Verona, Italy
Interests: biochemistry and molecular physiology of the photosynthetic process in higher plants and microalgae

Special Issue Information

Dear Colleagues,

Solar Energy is the most abundant renewable energy source available for our planet. Light energy conversion into chemical energy by photosynthetic organisms is, indeed, the process by which carbon dioxide is fixed in organic compounds. Exploitation of biomass produced by photosynthetic organisms is then at the base of heterotrophic metabolism. In addition, agriculture and several industrial processes rely on photosynthetic derived biomass, by which food, biofuels and high value products can be extracted. The molecular basis of both light and dark phase of photosynthesis have been investigated extensively in the past by multidisciplinary approaches ranging from biochemistry, biophysics, molecular biology and plant physiology. Fundamental knowledge of photosynthesis inspired several strategies to overcome bottlenecks in the whole process from light harvesting to biomass production. This Special Issue deals with the recent advances in the biochemistry and molecular physiology of the different steps of photosynthesis and their regulation. In this very wide context, we invite investigators to submit original research articles that explore different topics on the overall photosynthetic process including, but are not limited to:

  • Light harvesting and photoprotection in photosynthetic organisms
  • Biochemical and/or spectroscopic characterization of photosynthetic complexes
  • Regulation of light and dark phase of photosynthesis
  • Carbon fixation and photorespiration
  • Alternative electron transport in the chloroplast and their role in the photosynthetic process
  • Biotechnological strategies to increase biomass productivity in higher plants or microalgae

Assoc. Prof. Dr. Matteo Ballottari
Guest Editor

Manuscript Submission Information

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Keywords

  • Photosynthesis
  • Photoprotection
  • Microalgae
  • Biofuels
  • Light Harvesting
  • Carotenoids
  • Chlorophylls
  • Photosystem
  • Calvin cycle
  • Carbon fixation

Published Papers (13 papers)

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Research

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Open AccessArticle
Transcriptome Profile of the Variegated Ficus microcarpa c.v. Milky Stripe Fig Leaf
Int. J. Mol. Sci. 2019, 20(6), 1338; https://doi.org/10.3390/ijms20061338 - 16 Mar 2019
Cited by 1
Abstract
Photosynthetic properties and transcriptomic profiles of green and white sectors of Ficus microcarpa (c.v. milky stripe fig) leaves were examined in naturally variegated plants. An anatomic analysis indicated that chloroplasts of the white sectors contained a higher abundance of starch granules and lacked [...] Read more.
Photosynthetic properties and transcriptomic profiles of green and white sectors of Ficus microcarpa (c.v. milky stripe fig) leaves were examined in naturally variegated plants. An anatomic analysis indicated that chloroplasts of the white sectors contained a higher abundance of starch granules and lacked stacked thylakoids. Moreover, no photosynthetic rate was detected in the white sectors. Transcriptome profile and differential expressed gene (DEG) analysis showed that genes encoding PSII core proteins were down-regulated in the white sectors. In genes related to chlorophyll metabolism, no DEGs were identified in the biosynthesis pathway of chlorophyll. However, genes encoding the first step of chlorophyll breakdown were up-regulated. The repression of genes involved in N-assimilation suggests that the white sectors were deprived of N. The mutation in the transcription factor mitochondrial transcription termination factor (mTERF) suggests that it induces colorlessness in leaves of the milky stripe fig. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
Comparison on Photosynthesis and Antioxidant Defense Systems in Wheat with Different Ploidy Levels and Octoploid Triticale
Int. J. Mol. Sci. 2018, 19(10), 3006; https://doi.org/10.3390/ijms19103006 - 02 Oct 2018
Cited by 10
Abstract
To investigate the evolutionary differences of wheat with different ploidy levels and octoploid Triticale, photosynthetic capacity, and antioxidant defenses system were compared within and between diploid, tetraploid and hexaploid wheat, and octoploid Triticale seedlings. The results showed that seed germination rate, chlorophyll content, [...] Read more.
To investigate the evolutionary differences of wheat with different ploidy levels and octoploid Triticale, photosynthetic capacity, and antioxidant defenses system were compared within and between diploid, tetraploid and hexaploid wheat, and octoploid Triticale seedlings. The results showed that seed germination rate, chlorophyll content, and photochemical activity of photosystems, and the activities of antioxidative enzymes in hexaploid wheat and octoploid Triticale were significantly higher than in diploid and tetraploid wheat. Compared to other two wheat species and octoploid Triticale, hexaploid wheat presented lower levels of reactive oxygen species (ROS). Furthermore, we found that the levels of photosystem II reaction center protein D1, light-harvesting complex II b4 (CP29), and D subunit of photosystem I (PsaD) in diploid wheat were significantly lower compared with hexaploid wheat and octoploid Triticale. Taken together, we concluded that hexaploid wheat and octoploid Triticale have higher photosynthetic capacities and better antioxidant systems. These findings indicate that different ploidy levels of chromosome probably play an important regulatory role in photosystems and antioxidative systems of plants. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
Distinct Carbon and Nitrogen Metabolism of Two Contrasting Poplar Species in Response to Different N Supply Levels
Int. J. Mol. Sci. 2018, 19(8), 2302; https://doi.org/10.3390/ijms19082302 - 06 Aug 2018
Cited by 3
Abstract
Poplars have evolved various strategies to optimize acclimation responses to environmental conditions. However, how poplars balance growth and nitrogen deficiency remains to be elucidated. In the present study, changes in root development, carbon and nitrogen physiology, and the transcript abundance of associated genes [...] Read more.
Poplars have evolved various strategies to optimize acclimation responses to environmental conditions. However, how poplars balance growth and nitrogen deficiency remains to be elucidated. In the present study, changes in root development, carbon and nitrogen physiology, and the transcript abundance of associated genes were investigated in slow-growing Populus simonii (Ps) and fast-growing Populus euramericana (Pe) saplings treated with low, medium, and high nitrogen supply. The slow-growing Ps showed a flourishing system, higher δ15N, accelerated C export, lower N uptake and assimilation, and less sensitive transcriptional regulation in response to low N supply. The slow-growing Ps also had greater resistance to N deficiency due to the transport of photosynthate to the roots and the stimulation of root development, which allows survival. To support its rapid metabolism and growth, compared with the slow-growing Ps, the fast-growing Pe showed greater root development, C/N uptake and assimilation capacity, and more responsive transcriptional regulation with greater N supply. These data suggest that poplars can differentially manage C/N metabolism and photosynthate allocation under different N supply conditions. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
Effects of Different Metals on Photosynthesis: Cadmium and Zinc Affect Chlorophyll Fluorescence in Durum Wheat
Int. J. Mol. Sci. 2018, 19(3), 787; https://doi.org/10.3390/ijms19030787 - 09 Mar 2018
Cited by 25
Abstract
A comparative study of the effects of exposure to high Cd2+ (50 µM) and excess Zn2+ (600 µM) on photosynthetic performance of hydroponically-grown durum wheat seedlings was performed. At day 8, Cd and Zn were added to the nutrient solution. After [...] Read more.
A comparative study of the effects of exposure to high Cd2+ (50 µM) and excess Zn2+ (600 µM) on photosynthetic performance of hydroponically-grown durum wheat seedlings was performed. At day 8, Cd and Zn were added to the nutrient solution. After 7-days exposure, the chosen concentrations of both metals resulted in similar relative growth rate (RGR) inhibitions of about 50% and comparable retardations of the CO2 assimilation rates (about 30%) in the second developed leaf of wheat seedlings. Analysis of chlorophyll a fluorescence indicated that both metals disturbed photosynthetic electron transport processes which led to a 4- to 5-fold suppression of the efficiency of energy transformation in Photosystem II. Non-specific toxic effects of Cd and Zn, which prevailed, were an inactivation of part of Photosystem II reaction centres and their transformation into excitation quenching forms as well as disturbed electron transport in the oxygen-evolving complex. The specificity of the Cd and Zn modes of action was mainly expressed in the intensity of the toxicity effects: despite the similar inhibitions of the CO2 assimilation rates, the wheat photochemistry showed much more sensitivity to Cd than to Zn exposure. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
Biochemical and Physiological Characteristics of Photosynthesis in Plants of Two Calathea Species
Int. J. Mol. Sci. 2018, 19(3), 704; https://doi.org/10.3390/ijms19030704 - 01 Mar 2018
Abstract
Plants of the genus Calathea possess many leaf colors, and they are economically important because they are widely used as ornamentals for interior landscaping. Physiological performances and photosynthetic capacities of C. insignis and C. makoyana were investigated. The photosynthetic efficiencies of C. insignis [...] Read more.
Plants of the genus Calathea possess many leaf colors, and they are economically important because they are widely used as ornamentals for interior landscaping. Physiological performances and photosynthetic capacities of C. insignis and C. makoyana were investigated. The photosynthetic efficiencies of C. insignis and C. makoyana were significantly increased when the photosynthetic photon flux density (PPFD) increased from 0 to 600 μmol photons·m−2·s−1 and became saturated with a further increase in the PPFD. The two Calathea species had lower values of both the light saturation point and maximal photosynthetic rate, which indicated that they are shade plants. No significant differences in predawn Fv/Fm values (close to 0.8) were observed between dark-green (DG) and light-green (LG) leaf sectors in all tested leaves. However, the effective quantum yield of photosystem II largely decreased as the PPFD increased. An increase in the apparent photosynthetic electron transport rate was observed in both species to a maximum at 600 μmol·m−2·s−1 PPFD, following by a decrease to 1500 μmol·m−2·s−1 PPFD. Compared to LG leaf extracts, DG leaf extracts contained higher levels of chlorophyll (Chl) a, Chl b, Chls a + b, carotenoids (Cars), anthocyanins (Ants), flavonoids (Flas), and polyphenols (PPs) in all plants, except for the Ant, Fla and PP contents of C. insignis plants. Calathea insignis also contained significantly higher levels of total protein than did C. makoyana. The adjusted normalized difference vegetation index (NDVI), photochemical reflectance index (PRI), red-green, and flavonol index (FlavI) were significantly correlated to leaf Chls a + b, Cars, Ants, and Flas in C. makoyana, respectively, and can be used as indicators to characterize the physiology of these plants. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
LHCSR Expression under HSP70/RBCS2 Promoter as a Strategy to Increase Productivity in Microalgae
Int. J. Mol. Sci. 2018, 19(1), 155; https://doi.org/10.3390/ijms19010155 - 05 Jan 2018
Cited by 5
Abstract
Microalgae are unicellular photosynthetic organisms considered as potential alternative sources for biomass, biofuels or high value products. However, limited biomass productivity is commonly experienced in their cultivating system despite their high potential. One of the reasons for this limitation is the high thermal [...] Read more.
Microalgae are unicellular photosynthetic organisms considered as potential alternative sources for biomass, biofuels or high value products. However, limited biomass productivity is commonly experienced in their cultivating system despite their high potential. One of the reasons for this limitation is the high thermal dissipation of the light absorbed by the outer layers of the cultures exposed to high light caused by the activation of a photoprotective mechanism called non-photochemical quenching (NPQ). In the model organism for green algae Chlamydomonas reinhardtii, NPQ is triggered by pigment binding proteins called light-harvesting-complexes-stress-related (LHCSRs), which are over-accumulated in high light. It was recently reported that biomass productivity can be increased both in microalgae and higher plants by properly tuning NPQ induction. In this work increased light use efficiency is reported by introducing in C. reinhardtii a LHCSR3 gene under the control of Heat Shock Protein 70/RUBISCO small chain 2 promoter in a npq4 lhcsr1 background, a mutant strain knockout for all LHCSR genes. This complementation strategy leads to a low expression of LHCSR3, causing a strong reduction of NPQ induction but is still capable of protecting from photodamage at high irradiance, resulting in an improved photosynthetic efficiency and higher biomass accumulation. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
Estimation of Whole Plant Photosynthetic Rate of Irwin Mango under Artificial and Natural Lights Using a Three-Dimensional Plant Model and Ray-Tracing
Int. J. Mol. Sci. 2018, 19(1), 152; https://doi.org/10.3390/ijms19010152 - 04 Jan 2018
Cited by 4
Abstract
Photosynthesis is an important physiological response for determination of CO2 fertilization in greenhouses and estimation of crop growth. In order to estimate the whole plant photosynthetic rate, it is necessary to investigate how light interception by crops changes with environmental and morphological [...] Read more.
Photosynthesis is an important physiological response for determination of CO2 fertilization in greenhouses and estimation of crop growth. In order to estimate the whole plant photosynthetic rate, it is necessary to investigate how light interception by crops changes with environmental and morphological factors. The objectives of this study were to analyze plant light interception using a three-dimensional (3D) plant model and ray-tracing, determine the spatial distribution of the photosynthetic rate, and estimate the whole plant photosynthetic rate of Irwin mango (Mangifera indica L. cv. Irwin) grown in greenhouses. In the case of mangoes, it is difficult to measure actual light interception at the canopy level due to their vase shape. A two-year-old Irwin mango tree was used to measure the whole plant photosynthetic rate. Light interception and whole plant photosynthetic rate were measured under artificial and natural light conditions using a closed chamber (1 × 1 × 2 m). A 3D plant model was constructed and ray-tracing simulation was conducted for calculating the photosynthetic rate with a two-variable leaf photosynthetic rate model of the plant. Under artificial light, the estimated photosynthetic rate increased from 2.0 to 2.9 μmolCO2·m−2·s−1 with increasing CO2 concentration. On the other hand, under natural light, the photosynthetic rate increased from 0.2 μmolCO2·m−2·s−1 at 06:00 to a maximum of 7.3 μmolCO2·m−2·s−1 at 09:00, then gradually decreased to −1.0 μmolCO2·m−2·s−1 at 18:00. In validation, simulation results showed good agreement with measured results with R2 = 0.79 and RMSE = 0.263. The results suggest that this method could accurately estimate the whole plant photosynthetic rate and be useful for pruning and adequate CO2 fertilization. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
Participation of Green Organs to Grain Filling in Triticum turgidum var durum Grown under Mediterranean Conditions
Int. J. Mol. Sci. 2018, 19(1), 56; https://doi.org/10.3390/ijms19010056 - 25 Dec 2017
Cited by 2
Abstract
In wheat, flag leaf, stem, chaff and awns contribute to grain filling through photosynthesis and/or re-mobilization. Environmental and genetic effects on the relative contribution of each organ were examined by analyzing the consequences of sink-source manipulations (shading and excision) and by comparing carbon [...] Read more.
In wheat, flag leaf, stem, chaff and awns contribute to grain filling through photosynthesis and/or re-mobilization. Environmental and genetic effects on the relative contribution of each organ were examined by analyzing the consequences of sink-source manipulations (shading and excision) and by comparing carbon isotope discrimination (Δ) values in dry matter (at maturity) and sap (two weeks after anthesis) in six durum wheat genotypes grown in two contrasting seasons. The contribution of flag leaf, stem, chaff and awns to grain filling, estimated by sink-source manipulations, highly varied with the season. The contribution of ear photosynthesis and re-mobilization from the stem increased with post-anthesis water stress. They showed a large genetic variation that was, however, not clearly associated to morphological characteristics of ear and stem. Isotopic imprints of chaff on grain Δ were identified as a possible surrogate of the destructive and cumbersome sink-source manipulations to evaluate the contribution of carbon assimilated in ears or re-mobilized from stem. This might facilitate screening of genetic resources and allow the combining of favourable drought tolerance mechanisms in wheat. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessArticle
A RNA-Seq Analysis of the Response of Photosynthetic System to Low Nitrogen Supply in Maize Leaf
Int. J. Mol. Sci. 2017, 18(12), 2624; https://doi.org/10.3390/ijms18122624 - 05 Dec 2017
Cited by 5
Abstract
Nitrogen is a major limiting factor for crop productivity. The relationship between photosynthesis and nitrogen nutrition has been widely studied. However, the molecular response of leaf photosynthesis to low nitrogen supply in crops is less clear. In this study, RNA sequencing technology (RNA-Seq) [...] Read more.
Nitrogen is a major limiting factor for crop productivity. The relationship between photosynthesis and nitrogen nutrition has been widely studied. However, the molecular response of leaf photosynthesis to low nitrogen supply in crops is less clear. In this study, RNA sequencing technology (RNA-Seq) was used to investigate the gene expressions related to photosynthesis in maize in response to low nitrogen supply. It was found that low nitrogen supply down-regulated the expression of genes involved in photosystem I (PSI) and photosystem II (PSII). Thus, low nitrogen supply down-regulated the expression of genes related to the antenna system, reduced light absorption, light transport, and electron transport. Correspondingly, the parameters related to chlorophyll fluorescence were very sensitive to nitrogen deficiency. Under low nitrogen supply, leaf chlorophyll content, actual quantum yield of PSII photochemistry, photochemical quenching, and electron transport rate, were reduced. However, the thermal diffusion and chlorophyll fluorescence were increased. RNA-Seq was used to analyze the genes involved in the response of leaf photosynthesis to low nitrogen supply in maize. These results highlight the possibility of utilizing chlorophyll fluorescence parameters, and the related genes, as indicators for plant nitrogen nutrition. This could lead to the development of new tools to make precise nitrogen fertilizer recommendations and select nitrogen-efficient genotypes. Full article
(This article belongs to the Special Issue Photosynthesis)
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Review

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Open AccessReview
Chloroplasts at the Crossroad of Photosynthesis, Pathogen Infection and Plant Defense
by Yan Lu and Jian Yao
Int. J. Mol. Sci. 2018, 19(12), 3900; https://doi.org/10.3390/ijms19123900 - 05 Dec 2018
Cited by 3
Abstract
Photosynthesis, pathogen infection, and plant defense are three important biological processes that have been investigated separately for decades. Photosynthesis generates ATP, NADPH, and carbohydrates. These resources are utilized for the synthesis of many important compounds, such as primary metabolites, defense-related hormones abscisic acid, [...] Read more.
Photosynthesis, pathogen infection, and plant defense are three important biological processes that have been investigated separately for decades. Photosynthesis generates ATP, NADPH, and carbohydrates. These resources are utilized for the synthesis of many important compounds, such as primary metabolites, defense-related hormones abscisic acid, ethylene, jasmonic acid, and salicylic acid, and antimicrobial compounds. In plants and algae, photosynthesis and key steps in the synthesis of defense-related hormones occur in chloroplasts. In addition, chloroplasts are major generators of reactive oxygen species and nitric oxide, and a site for calcium signaling. These signaling molecules are essential to plant defense as well. All plants grown naturally are attacked by pathogens. Bacterial pathogens enter host tissues through natural openings or wounds. Upon invasion, bacterial pathogens utilize a combination of different virulence factors to suppress host defense and promote pathogenicity. On the other hand, plants have developed elaborate defense mechanisms to protect themselves from pathogen infections. This review summarizes recent discoveries on defensive roles of signaling molecules made by plants (primarily in their chloroplasts), counteracting roles of chloroplast-targeted effectors and phytotoxins elicited by bacterial pathogens, and how all these molecules crosstalk and regulate photosynthesis, pathogen infection, and plant defense, using chloroplasts as a major battlefield. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessReview
Optimization of Photosynthetic Productivity in Contrasting Environments by Regulons Controlling Plant Form and Function
Int. J. Mol. Sci. 2018, 19(3), 872; https://doi.org/10.3390/ijms19030872 - 15 Mar 2018
Cited by 6
Abstract
We review the role of a family of transcription factors and their regulons in maintaining high photosynthetic performance across a range of challenging environments with a focus on extreme temperatures and water availability. Specifically, these transcription factors include CBFs (C-repeat binding factors) and [...] Read more.
We review the role of a family of transcription factors and their regulons in maintaining high photosynthetic performance across a range of challenging environments with a focus on extreme temperatures and water availability. Specifically, these transcription factors include CBFs (C-repeat binding factors) and DREBs (dehydration-responsive element-binding), with CBF/DREB1 primarily orchestrating cold adaptation and other DREBs serving in heat, drought, and salinity adaptation. The central role of these modulators in plant performance under challenging environments is based on (i) interweaving of these regulators with other key signaling networks (plant hormones and redox signals) as well as (ii) their function in integrating responses across the whole plant, from light-harvesting and sugar-production in the leaf to foliar sugar export and water import and on to the plant’s sugar-consuming sinks (growth, storage, and reproduction). The example of Arabidopsis thaliana ecotypes from geographic origins with contrasting climates is used to describe the links between natural genetic variation in CBF transcription factors and the differential acclimation of plant anatomical and functional features needed to support superior photosynthetic performance in contrasting environments. Emphasis is placed on considering different temperature environments (hot versus cold) and light environments (limiting versus high light), on trade-offs between adaptations to contrasting environments, and on plant lines minimizing such trade-offs. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessReview
Formation and Change of Chloroplast-Located Plant Metabolites in Response to Light Conditions
Int. J. Mol. Sci. 2018, 19(3), 654; https://doi.org/10.3390/ijms19030654 - 26 Feb 2018
Cited by 7
Abstract
Photosynthesis is the central energy conversion process for plant metabolism and occurs within mature chloroplasts. Chloroplasts are also the site of various metabolic reactions involving amino acids, lipids, starch, and sulfur, as well as where the production of some hormones takes place. Light [...] Read more.
Photosynthesis is the central energy conversion process for plant metabolism and occurs within mature chloroplasts. Chloroplasts are also the site of various metabolic reactions involving amino acids, lipids, starch, and sulfur, as well as where the production of some hormones takes place. Light is one of the most important environmental factors, acting as an essential energy source for plants, but also as an external signal influencing their growth and development. Plants experience large fluctuations in the intensity and spectral quality of light, and many attempts have been made to improve or modify plant metabolites by treating them with different light qualities (artificial lighting) or intensities. In this review, we discuss how changes in light intensity and wavelength affect the formation of chloroplast-located metabolites in plants. Full article
(This article belongs to the Special Issue Photosynthesis)
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Open AccessReview
Genetic and Hormonal Regulation of Chlorophyll Degradation during Maturation of Seeds with Green Embryos
Int. J. Mol. Sci. 2017, 18(9), 1993; https://doi.org/10.3390/ijms18091993 - 16 Sep 2017
Cited by 3
Abstract
The embryos of some angiosperms (usually referred to as chloroembryos) contain chlorophylls during the whole period of embryogenesis. Developing embryos have photochemically active chloroplasts and are able to produce assimilates, further converted in reserve biopolymers, whereas at the late steps of embryogenesis, seeds [...] Read more.
The embryos of some angiosperms (usually referred to as chloroembryos) contain chlorophylls during the whole period of embryogenesis. Developing embryos have photochemically active chloroplasts and are able to produce assimilates, further converted in reserve biopolymers, whereas at the late steps of embryogenesis, seeds undergo dehydration, degradation of chlorophylls, transformation of chloroplast in storage plastids, and enter the dormancy period. However, in some seeds, the process of chlorophyll degradation remains incomplete. These residual chlorophylls compromise the quality of seed material in terms of viability, nutritional value, and shelf life, and represent a serious challenge for breeders and farmers. The mechanisms of chlorophyll degradation during seed maturation are still not completely understood, and only during the recent decades the main pathways and corresponding enzymes could be characterized. Among the identified players, the enzymes of pheophorbide a oxygenase pathway and the proteins encoded by STAY GREEN (SGR) genes are the principle ones. On the biochemical level, abscisic acid (ABA) is the main regulator of seed chlorophyll degradation, mediating activity of corresponding catabolic enzymes on the transcriptional level. In general, a deep insight in the mechanisms of chlorophyll degradation is required to develop the approaches for production of chlorophyll-free high quality seeds. Full article
(This article belongs to the Special Issue Photosynthesis)
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