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Advances in Plastid Biology and Its Applications

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Nguyễn Gia Hào

Academic year: 2023

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RPW8.2 localizes to the extrahaustorial membrane (EHM) during fungal penetration into the host cell ( Wang et al., 2009 ). In addition to BYPASS1 (BPS1), two additional BPS genes (BPS2 and BPS3) were identified in Arabidopsis and the bpstriple mutant (bps1bps2bps3) has aberrant cell division during early embryogenesis resulting in SAM, root apical and vamoric meristem (RAM) defects et al. ., 2012).

FIGURE 1 | Routes for chloroplast signaling. (A) Chloroplasts generate signals that target multiple intercellular targets
FIGURE 1 | Routes for chloroplast signaling. (A) Chloroplasts generate signals that target multiple intercellular targets

INTRODUCTION

In fact, the promoter of the Lhcb6 (cab-6) gene from black pine, which encodes a form of the apoprotein of the main light-harvesting complex of photosystem II, is able to drive the expression of a beta-glucoronidase (GUS) reporter gene. constitutively in the dark in an angiosperm, tobacco (Kojima et al., 1994). The activity of these repressors is abrogated in light by photoreceptor activation ( Jiao et al., 2007 ; Lau and Deng, 2012 ).

MATERIALS AND METHODS Plant Material, Light, and Growth

The result is extensive reprogramming of the transcriptome of seedlings when they are first exposed to light (Jiao et al., 2007). RNA was extracted as previously described after 7 days (tobacco) or 5 days (Arabidopsis) of seedling growth in continuous light or continuous darkness (Vinti et al., 2000).

FIGURE 1 | Morphology and RNA gel blot analysis showing the response of the pine Lhcb promoter to light in tobacco seedlings.
FIGURE 1 | Morphology and RNA gel blot analysis showing the response of the pine Lhcb promoter to light in tobacco seedlings.

RESULTS

Activity of the pineLhcb promoter (represented by steady-state GUSmRNA levels) was clearly sensitive to norflurazone treatment in the light ( Figure 2A ). Plastid translation inhibition caused decreases in Lhcb, relative to Act, in the dark and in the light (Figure 4, blot quantification provided in Supplementary Figure S2).

FIGURE 4 | Response of pine seedlings to light treatments or treatments affecting plastidviability
FIGURE 4 | Response of pine seedlings to light treatments or treatments affecting plastidviability

DISCUSSION

Genetic screens for light defects in plastid-to-nucleus communication identified mutant alleles of the photoreceptor CRYPTOCHROME 1 and of HY5 ( Ruckle et al., 2007 ) effective even in the absence of light. It was useful to note the differences in the responses of two mutants with non-functional plastids, ppi1 and cue8.

FIGURE 7 | RNA gel blot analysis showing the genetic interaction between plastid developmental mutations (ppi1 and cue8) and de-etiolated mutations (cop1 and det1) in Arabidopsis
FIGURE 7 | RNA gel blot analysis showing the genetic interaction between plastid developmental mutations (ppi1 and cue8) and de-etiolated mutations (cop1 and det1) in Arabidopsis

AUTHOR CONTRIBUTIONS

While DET1 acts as a repressor of PhANG expression in the dark, its loss also causes a reduction of expression in the light (Figures 7 and especially 8). Instead, the evidence supports their direct role in the expression of a subset of genes.

FUNDING

Therefore, defects in PhANG expression extended to most of the PhANGs tested (see Figures 6–8 ), but were clearly evident in the light, being mild ( Figures 6 and 7 ) or barely, if at all, detectable ( Figure 8) in the dark. While lincomycin is a translation inhibitor that specifically affects chloroplast ribosomes (see Gray et al., 2003), regardless of light, germination-applied norflurazon has been shown to prevent functional assembly of the photosynthetic membrane complex in light (Voigt; , 201 al. Apel, 2013).

ACKNOWLEDGMENTS

This apparent action of DET1 as a repressor in the dark and an activator in the light seems paradoxical, but has been observed in the past (Chory et al., 1989; Ruckle et al., 2012), and may be related to oxidative damage, which could also explain the large increase in CHS (photoprotectant) expression. Perhaps an unexpected consequence of the current work is that current advances in understanding terminal, mechanistic steps in both light and plastid-to-nucleus signaling action could lead to mutually revealing findings, and could provide an ultimate goal of rational engineering of chloroplast biogenesis. to help.

SUPPLEMENTARY MATERIAL

On the other hand, CUE8 encodes a chloroplast housekeeping protein, defects in which cause altered etioplast and chloroplast development (Vinti et al., 2005). Interestingly, the response of LHCBs in glk1 glk2 mutants to light was mildly affected, but expression clearly did not occur in such mutants in the dark, even in the absence of DET1, revealing GLKs as potential targets for dark repression of LHCBs from DET1.

We also measured TAG levels in the roots of WT Arabidopsis plants grown under Pi-sufficient and Pi-depleted conditions. Indeed, Arabidopsis WT plants under Pi-depleted conditions retain ∼85% of their photosynthetic activity compared to plants grown under Pi-sufficient conditions ( Kobayashi et al., 2009 ).

FIGURE 1 | Sequential amplification, cloning, and development of pMSK83 chloroplast transformation vector
FIGURE 1 | Sequential amplification, cloning, and development of pMSK83 chloroplast transformation vector

WHY CHLOROPLASTS?

Use of vaccines can be an effective strategy that can be used either prophylactically (before disease onset) or therapeutically (after disease onset). Therefore, alternative strategies must be chosen to cover the shortcomings of vaccines in use.

PLASTID TRANSFORMATION

After transformation, several rounds of selection and regeneration are required on selection medium containing appropriate antibiotics to regenerate the homoplasmic transplastomic plants (Verma et al., 2008; Ahmad and Mukhtar, 2013). If these leaves are used for transformation, homoplasmy can be obtained more quickly during the regeneration phase.

STABLE GENETIC RESOURCE

Combinations of similar insertion sites, promoters, regulatory elements and terminators are shown in one color. Whole transplastomic plants are regenerated under controlled aseptic conditions and acclimatized in the greenhouse for further growth.

POLYPLOIDY AND VERY HIGH

SM, selection marker; RE, regulatory elements; UTR, untranslated region; psbA, psbA gene; TpsbA, terminator of the psbA gene; rrn16, rrn 16 gene; T7g10, leader sequence of phage lambda T7 gene 10; rbcL, rbcL gene; TrbcL, rbcL gene terminator; TrrnB, Escherichia colirrnB terminator; TSP, total soluble protein; TLP, total leaf protein.

EXPRESSION OF FOREIGN PROTEINS

However, this does not seem to be a reality at the current stage due to a number of limitations (for detailed discussion on this topic see Rybicki, 2009). Thus, for vaccine production, a high protein producing platform such as chloroplasts should be selected.

ABSENCE OF EPIGENETIC EFFECTS

In contrast, if protein purification has to be done, then the cost reduction is only significant at the production level, which is estimated to be around 31% (Rybicki, 2009). This feature is expected to further reduce costs at the production level because more protein will be produced per kilogram of plant weight.

EXPRESSION OF MULTIGENES AS SINGLE OPERON

Higher the term less will be the cost of the final product because more product will be produced from fewer resources. However, this also depends on a number of other factors such as the use of plants with broad leaves and high biomass.

SAFETY OF

For vaccine production at a cost-effective rate, this very high expression may play a key role. Various antigen-based vaccine candidates have been expressed in chloroplasts against a number of human diseases.

PLANTS/CHLOROPLAST-DERIVED VACCINES

The potential oral administration of herbal vaccines, which, if in fact possible, will also greatly reduce costs by eliminating expensive further processing. In such a case, the use of chloroplast-based expression and homoplasmy in which all plastomes are in a transformed state can lead to very high expression.

MATERNAL INHERITANCE OF PLASTID GENOME

Rotavirus VP6 gene (gastroenteritis) Tobacco >15% of total leaf protein (TLP) Not tested Inka Borchers et al., 2012 BACTERIAL ANTIGENS. The risk is further reduced by the fact that plants naturally harbor many bacteria that contain antibiotic resistance genes (Nielsen et al., 1998).

TABLE 1 | Different vaccine antigens against human diseases expressed via plastid genome since 2011.
TABLE 1 | Different vaccine antigens against human diseases expressed via plastid genome since 2011.

STABILITY OF

In general, the risk of horizontal gene transfer from plants to microorganisms, especially when transformed plants contain antibiotic resistance genes, is very low and there is no existing report of such occurrence (Obembe et al., 2011). Therefore, it can be argued that horizontal gene transfer to soil bacteria is very negligible.

PLANT/CHLOROPLAST-EXPRESSED PROTEINS

Considering the benefit of chloroplast transformation associated with transgene inclusion, it is very likely that field trials in isolated areas at the local level in developing countries could be allowed after the containment issues are addressed to the local authorities. Alternatively, plant-derived vaccines can be purified and freeze-dried for storage at room temperatures and transported when needed.

WHAT NEXT?

Exhaustion of chloroplast protein synthesis capacity by mass expression of a highly stable protein antibiotic. Bima J. High-level expression of human immunodeficiency virus antigens from tobacco and tomato plastid genomes. Plant Biotechnology.

CHLOROPLAST TRANSFORMATION SYSTEMS

This cassette promoted the expression of a foreign gene together with the selection marker (Xie et al., 2014). The highest expression of soluble GUS was recorded for the atpA promoter and 5'UTR (Ishikura et al., 1999).

TABLE 1 | List of selection markers and selection modes for chloroplast transformation.
TABLE 1 | List of selection markers and selection modes for chloroplast transformation.

NUCLEAR TRANSFORMATION

In the unicellular green alga Lobosphaera (Parietochloris) incisa, the endogenous RBCS promoter was used to drive expression of the blegen, creating a platform for future successful engineering of this alga, which has great biotechnological potential due to its polyunsaturated fatty acid with long chain. (PUFA) metabolism (Zorin et al., 2014). Photoautotrophic growth Chlamydomonas reinhardtii (oee1-).. Lin et al., 2010), allowing growth in the absence of nicotinamide.

TABLE 3 | List of selection markers and selection modes for nuclear transformation.
TABLE 3 | List of selection markers and selection modes for nuclear transformation.

BIOTECHNOLOGICAL EXPLOITATION OF MICROALGAE

This study established the possibility of improving the production of H2 from H2O and glucose (Doebbe et al., 2007). Contained growth can be carried out in closed bioreactors (Chaumont, 1993), tubular reactors (Richmond et al., 1993) or polyethylene envelopes (Cohen et al., 1991).

CONCLUSIONS AND FUTURE PERSPECTIVES

Studies on the conservation and expression of cloned DNA fragments in the nuclear genome of the green alga Chlamydomonas reinhardtii.Physiol. Characterization of Dunaliella tertiolecta RbcS genes and their promoter activity in Chlamydomonas reinhardtii. Rep. of plant cells.

MATERIALS AND METHODS

Our previous study showed that the IEM targeting signal is sufficient to deliver the chimeric protein to the chloroplast IEM in vivo ( Okawa et al., 2014 ). Bicarbonate transporters can reside in the chloroplast IEM even after removal of the IEM targeting signal.

FIGURE 1 | Construct designs for specific targeting of bicarbonate transporters to the chloroplast IEM
FIGURE 1 | Construct designs for specific targeting of bicarbonate transporters to the chloroplast IEM

CONCLUSION

To gain insight into epidermal plastid distribution, we performed intensive observations of plastid morphology in the leaf epidermis of A. The AtminE1 mutant also exhibited a unique morphological feature in the plastid bodies in the leaf epidermis.

FIGURE 1 | Utility of cyan fluorescent protein (CFP) to investigate plastid morphology in Arabidopsis leaf epidermis
FIGURE 1 | Utility of cyan fluorescent protein (CFP) to investigate plastid morphology in Arabidopsis leaf epidermis

DIURNAL CHANGES IN PLASTID MORPHOLOGY

Targeting GFP to the stroma (Köhler et al., 1997) was one of the first successful demonstrations. It is also worth noting that the main conclusions of Brunkard et al. 2015) are based on observation of excised cotyledons rather than true, photosynthesizing leaves.

FIGURE 1 | Representative images of fluorescently highlighted plastids and some sub-plastidic features
FIGURE 1 | Representative images of fluorescently highlighted plastids and some sub-plastidic features

CHLOROPLAST PROTRUSIONS AND STROMULES: AN ARTIFICIAL

Interestingly, a number of publications document the presence of chloroplasts in epidermal induration cells in Arabidopsis (Robertson et al., 1996; Vitha et al., 2001; Joo et al., 2005). Plastids in both injured and aging tissue are known to exhibit increased stromule frequency (Krupinska, 2007; Ishida et al., 2008).

DISTINCTION?

Using static photographs, Holzinger et al. 2007b) had demonstrated that mean shape indices can be grouped into two populations, one with mean 0.8±0.3 and the other 7±1.3. Equally interesting is a comprehensive contextual review citing Holzinger et al. 2007b) publication as strong evidence of differences between CP and stromules, but also presents a table listing Arabidopsis as a non-CP-producing plant (Lütz, 2010).

THE NOTION OF PROTEIN EXCHANGE BETWEEN INDEPENDENT PLASTIDS

Leukoplasts with very similar morphology were used in FRAP experiments to establish the idea of ​​FP flow between plastids (Köhler et al., 1997). Alternatively, it has led to the ectopic proliferation of membranes (Oikawa et al., 2008; Breuers et al., 2012).

FIGURE 3 | The use of a stroma targeted green to red photo-convertible mEosFP for differential coloring of plastids allowed the long-standing idea of plastid-interconnectivity through stromules to be reassessed
FIGURE 3 | The use of a stroma targeted green to red photo-convertible mEosFP for differential coloring of plastids allowed the long-standing idea of plastid-interconnectivity through stromules to be reassessed

FP-AIDED INSIGHTS ON PLASTID INTERACTIONS

In several cases, the overexpression of such fusion proteins led to observations of protein spots on the plastid envelope (Seo et al., 2009; Tan et al., 2011). Since plastoglobules can be easily purified biochemically and subjected to proteomics (Ytterberg et al., 2006; Nacir and Bréhélin, 2013), the FP probes for plastoglobuli (Table 1) are currently rather underutilized.

TABLE 2 | Some proteins that show multiple localizations.
TABLE 2 | Some proteins that show multiple localizations.

PLASTIDS AND THE CYTOSKELETON

PLASTIDS AND THE ENDOPLASMIC RETICULUM

THE PLASTID-NUCLEUS RELATIONSHIP AND VIEWS ON RETROGRADE SIGNALING

Perhaps the observations are due to physiological disruption of the cell during infection and do not indicate stromal function (Krenz et al., 2012). The accumulation of untargeted FP in the nucleus is one of the main caveats associated with their use (Haseloff et al., 1997; Mathur et al., 2010).

FIGURE 4 | Visualization of different colored FP to specific organelles facilitates investigations on plastid interactions
FIGURE 4 | Visualization of different colored FP to specific organelles facilitates investigations on plastid interactions

COMPREHENSIVE VIEW OF THE PLASTID DIVISION PROCESS

The diurnal cycle of stromules, either in response to a change in chloroplast redox status or a change in cellular sugar levels, is quite clear (Schattat and Klösgen, 2011; Schattat et al., 2012a; Brunkard et al., 2015). The use of Agrobacterium-mediated overexpression of proteins under consideration again suggests caution in the interpretations, as the infiltration of Agrobacterium itself has been shown to increase stromule frequency (Schattat et al., 2012b; Erickson et al., 2014).

INSIGHTS INTO PLASTID BREAKDOWN USING FPs

Formation of the disulfide bridge causes a conformational change that shifts the excitation maxima and allows ratiometric quantification of the reduced glutathione pool in a living cell (Hanson et al., 2004;. Another FP used to directly estimate the relative concentrations of H2O2 is the modified YFP known as HyPer (Costa et al., 2010).

FUTURE PROSPECTS FOR FP BASED INVESTIGATIONS ON PLASTIDS

Expression and characterization of a redox-sensing green fluorescent protein (reduction-oxidation-sensitive green fluorescent protein) in Arabidopsis.Plant Physiol. PDV1 and PDV2 mediate recruitment of the dynamin-related protein ARC5 to the plastid division site. Plant cell.

MATERIALS AND METHODS Planting and Growing Conditions

We provide an analysis of the effects of T-DNA insertion mutations in each of the DNA polymerase genes on plant growth and development and chloroplast genome copy numbers. The expression of DNA polymerase genes appears to be very high in newly developing tissues, especially in meristems (Kimura et al., 2002).

FIGURE 1 | Map of the DNA polymerase genes and T-DNA insertions. Note the overall similarity between both genes for Pol1A and Pol1B
FIGURE 1 | Map of the DNA polymerase genes and T-DNA insertions. Note the overall similarity between both genes for Pol1A and Pol1B

Hình ảnh

FIGURE 2 | Mechanisms of chloroplast-to-nucleus signaling. (A) Retrograde signaling by PAP
FIGURE 3 | Chloroplast proteins as retrograde signals. A few chloroplast proteins have been implicated in directly modulating nuclear gene expression by their nuclear localization
FIGURE 4 | Arrangement of organelles in a leaf cell. Transmission electron microscopy images often reveal chloroplasts in close proximity with peroxisomes and mitochondria
FIGURE 1 | Biogenetic relationships of carotenoid-derived signal molecules in Arabidopsis
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