Regulation Mechanism of Exogenous Brassinolide on Bulbil Formation and Development in Pinellia ternata

The bulbil is the propagative organ of the P. ternata, which has a great effect on the yield of P. ternata. It is well known that plant hormones play important roles in bulbil formation and development. However, there is not clear about brassinolide (BR) regulation on bulbil formation and development. In this study, we revealed the effects of BR and BR biosynthesis inhibitors (propiconazole, Pcz) application on the histological observation, starch and sucrose metabolism, photosynthesis pathway, and hormone signaling pathway of P. ternata. The results showed that BR treatment reduced starch catabolism to maltodextrin and maltose in bulbil by decreasing BAM and ISA genes expression and increased cellulose catabolism to D-glucose in bulbil by enhancing edg and BGL genes expression. BR treatment enhanced the photosynthetic pigment content and potential maximum photosynthetic capacity and improved the photoprotection ability of P. ternata by increasing the dissipation of excess light energy to heat, thus reduced the photodamage in the PSII center. BR treatment increased the GA and BR content in bulbil of P. ternata, and decreased the ABA content in bulbil of P. ternata. Pcz treatment increased the level of GA, SL, ABA, and IAA in bulbil of P. ternata. BR regulated the signal transduction of BR, IAA, and ABA to regulate the formation and development of bulbil in P. ternata. These results provide molecular insight into BR regulation on bulbil formation and development.

Comparative Genome Analysis of Genes Regulating Compound Inflorescences in Tomato

Inflorescences are the main factor affecting fruit yield. The quantity and quality of inflorescences are closely related to fruit quality and yield. The presence of compound inflorescences in cherry tomatoes is well established, and it has been discovered by chance that compound racemes also exist in tomatoes. To explore the formation of compound inflorescences in tomato, transcriptome sequencing was performed on Moneymaker (MM) and Compound Inflorescence (CI) plants. In-florescences were collected in three periods (early, middle and late) in three replicates, for a total of 18 samples. Data analysis showed that the DEGs were most enriched in metabolic pathways and plant hormone signal transduction pathways. The DEGs were also enriched in the cell cycle pathway, photosynthesis pathway, carbon metabolism pathway and circadian rhythm pathway. We found that the FALSIFLORA (FA), COMPOUND INFLORESCENCE (S) and ANANTHA (AN) genes were involved in compound inflorescence development, not only revealing novel genes but also providing a rich theoretical basis for compound inflorescence development.

Extraterrestrial Photosynthesis by Chang’E-5 Lunar Soil

In light of significant effort conducted to manned deep space exploration, it is of high technological importance and scientific interest to develop the lunar life supporting system for long-term exploration and exploitation. And lunar in situ resource utilization offers great opportunity to provide the material basis of life supporting for lunar habitation and traveling. Based on the analysis of the structure and composition, the Chang’E-5 lunar soil sample was used for lunar-surface solar energy conversion, i.e. the extraterrestrial photosynthesis catalysts. By evaluating the performance of the Chang’E-5 lunar sample as photovoltaic-driven electrocatalyst, photocatalyst and photothermal catalysts, the full water splitting and CO2 conversion are able to be achieved with solar energy, water and lunar soil, with a wide range of product distribution, including O2, H2, CO, CH4 and CH3OH. Thus, we propose a potentially available extraterrestrial photosynthesis pathway on the moon, which could help us to achieve a ‘zero-energy consumption’ environment and life support system on the moon.

Physiological Adaptation And Transcriptome Changes In The Plateau Plant Common Vetch (Vicia Sativa L.) In Response To The Plain Environment

Common vetch (Vicia sativa L.) is an annual herb with high nutritional value, strong adaptability and cold tolerance. It is one of the forage varieties widely planted in the construction of artificial grassland in Qinghai Tibet Plateau. In order to reveal the molecular regulation mechanism of common vetch introduced into plain, physiological and transcriptome analysis of common vetch seedlings in Plateau and plain environment were carried out. In the plain environment, the leaf structure and some physiological indexes of common vetch can adapt to the plain environment gradually and keep stable. However, the maximum photochemical quantum yield (fv/fm) and chlorophyll content (Chl) of PSII fluctuated and could not keep stable. Further transcriptome sequencing showed that there were many different genes involved in photosynthesis pathway, photosynthetic antenna protein pathway, carbon dioxide fixation pathway in photosynthetic organisms and porphyrin and chlorophyll metabolism pathway in plain environment. Similarly, TF analysis showed that MYB, NAC, AP2-EREBP and Orphans were the main transcription factors involved in the adaptation of common vetch to the changes of plain environment. These results may explain that the main reason why the common vetch is not suitable for the plain environment is the difference of the light intensity between the plain and the plateau. These findings provide a theoretical basis for scientific introduction and breeding of new varieties from plateau to plain.

A conserved C-terminal peptide of sorghum phosphoenolpyruvate carboxylase promotes its proteolysis, which is prevented by Glc-6P or the phosphorylation state of the enzyme

Main conclusion A synthetic peptide from the C-terminal end of C4-phosphoenolpyruvate carboxylase is implicated in the proteolysis of the enzyme, and Glc-6P or phosphorylation of the enzyme modulate this effect. Abstract Phosphoenolpyruvate carboxylase (PEPC) is a cytosolic, homotetrameric enzyme that performs a variety of functions in plants. Among them, it is primarily responsible for CO2 fixation in the C4 photosynthesis pathway (C4-PEPC). Here we show that proteolysis of C4-PEPC by cathepsin proteases present in a semi-purified PEPC fraction was enhanced by the presence of a synthetic peptide containing the last 19 amino acids from the C-terminal end of the PEPC subunit (pC19). Threonine (Thr)944 and Thr948 in the peptide are important requirements for the pC19 effect. C4-PEPC proteolysis in the presence of pC19 was prevented by the PEPC allosteric effector glucose 6-phosphate (Glc-6P) and by phosphorylation of the enzyme. The role of these elements in the regulation of PEPC proteolysis is discussed in relation to the physiological context.

Exploring Grass Morphology & Mutant Phenotypes Using Setaria viridis

Globally, most human caloric intake is from crops that belong to the grass family (Poaceae), including sugarcane (Saccharum spp.), rice (Oryza sativa), maize (or corn, Zea mays), and wheat (Triticum aestivum). The grasses have a unique morphology and inflorescence architecture, and some have also evolved an uncommon photosynthesis pathway that confers drought and heat tolerance, the C4 pathway. Most secondary-level students are unaware of the global value of these crops and are unfamiliar with plant science fundamentals such as grass architecture and the genetic concepts of genotype and phenotype. Green foxtail millet (Setaria viridis) is a model organism for C4 plants and a close relative of globally important grasses, including sugarcane. It is ideal for teaching about grass morphology, the economic value of grasses, and the C4 photosynthetic pathway. This article details a teaching module that uses S. viridis to engage entire classrooms of students in authentic research through a laboratory investigation of grass morphology, growth cycle, and genetics. This module includes protocols and assignments to guide students through the process of growing one generation of S. viridis mutants and reference wild-type plants from seed to seed, taking measurements, making critical observations of mutant phenotypes, and discussing their physiological implications.

ZmFdC2 Encoding a Ferredoxin Protein With C-Terminus Extension Is Indispensable for Maize Growth

As important electron carriers, ferredoxin (Fd) proteins play important roles in photosynthesis, and the assimilation of CO2, nitrate, sulfate, and other metabolites. In addition to the well-studied Fds, plant genome encodes two Fd-like protein members named FdC1 and FdC2, which have extension regions at the C-terminus of the 2Fe-2S cluster. Mutation or overexpression of FdC genes caused alterations in photosynthetic electron transfer rate in rice and Arabidopsis. Maize genome contains one copy of each FdC gene. However, the functions of these genes have not been reported. In this study, we identified the ZmFdC2 gene by forward genetics approach. Mutation of this gene causes impaired photosynthetic electron transport and collapsed chloroplasts. The mutant plant is seedling-lethal, indicating the indispensable function of ZmFdC2 gene in maize development. The ZmFdC2 gene is specifically expressed in photosynthetic tissues and induced by light treatment, and the encoded protein is localized on chloroplast, implying its specialized function in photosynthesis. Furthermore, ZmFdC2 expression was detected in both mesophyll cells and bundle sheath cells, the two cell types specialized for C4 and C3 photosynthesis pathways in maize. Epigenomic analyses showed that ZmFdC2 locus was enriched for active histone modifications. Our results demonstrate that ZmFdC2 is a key component of the photosynthesis pathway and is crucial for the development of maize.

The inhibition of photosynthesis of Angelica dahurica caused by early bolting

Background Ealy bolting affects the photosynthesis of plants. However, there are positive or negative impacts in different plants. The mechanism of photosynthesis pathway respond to early bolting is still a mystery. Angelica dahurica is a traditional Chinese medical plant that has been used as the raw material of medicine and food. Early bolting of Angelica dahurica occurring in the field production, which decreases quality and yield of A. dahurica. Results In this research, we firstly revealed the damage of early bolting on the photosynthesis of A. dahurica. The photosynthetic capacity significantly decreased after bolting. The metabonomic analysis showed that the chlorophyll synthesis metabolism was repressed and the accumulation of saturated fatty acid increased after early bolting. Meanwhile, transcriptomic analysis indicated a down-regulation of photosynthetic electron transport and up-regulation of saturated fatty acid synthesis. Interestedly, an unexpected raise in Rubisco and PEPC activities of the leaves of early bolting plants was found in our research. Conclusion The photosynthesis is repressed by early bolting in transcriptomics and metabonomics. Meanwhile, early bolting induced accumulation of saturated fatty acid and increased the activities of PEPC and Rubisco. It suggested a special mediated way responds to the inhibition of photosynthesis of A. dahurica by early bolting.

Metabolomic and transcriptomic analyses of mutant yellow leaves provide insights into pigment synthesis and metabolism in Ginkgo biloba

Background Ginkgo (Ginkgo biloba L.) is an excellent landscape species. Its yellow-green leaf mutants are ideal materials for research on pigment synthesis, but the regulatory mechanism of leaf coloration in these ginkgo mutants remains unclear. Results We compared the metabolomes and transcriptomes of green and mutant yellow leaves of ginkgo over the same period in this study. The results showed that the chlorophyll content of normal green leaves was significantly higher than that of mutant yellow leaves of ginkgo. We obtained 931.52M clean reads from different color leaves of ginkgo. A total of 283 substances in the metabolic profiles were finally detected, including 50 significantly differentially expressed metabolites (DEMs). We identified these DEMs and 1361 differentially expressed genes (DEGs), with 37, 4, 3 and 13 DEGs involved in the photosynthesis, chlorophyll, carotenoid, and flavonoid biosynthesis pathways, respectively. Moreover, integrative analysis of the metabolomes and transcriptomes revealed that the flavonoid pathway contained the upregulated DEM (−)-epicatechin. Fourteen DEGs from the photosynthesis pathway were positively or negatively correlated with the DEMs. Conclusions Our findings suggest a complex metabolic network in mutant yellow leaves. This study will provide a basis for studies of leaf color variation and regulation.

Comparative physiological and transcriptomic analyses of photosynthesis in Sphagneticola calendulacea (L.) Pruski and Sphagneticola trilobata (L.) Pruski

Sphagneticola trilobata (L.) Pruski is one of the fast-growing malignant weeds in South China. It has severely influenced local biodiversity and native plant habitat. Photosynthesis is the material basis of plant growth and development. However, there are few reports on the photosynthetic transcriptome of S. trilobata. In this study, S. trilobata had a relatively large leaf area and biomass. The gas exchange parameters per unit area of leaves, including net photosynthetic capacity (Pn), intercellular CO2 (Ci), stomatal conductance (Gs), transpiration rate (Tr), water use efficiency (WUE), photosynthetic pigment and Rubisco protein content were higher than those of the native plant Sphagneticola calendulacea (L.) Pruski. On this basis, the differences in photosynthesis pathways between the two Sphagneticola species were analyzed by using the Illumina HiSeq platform. The sequencing results for S. trilobata and S. calendulacea revealed 159,366 and 177,069 unigenes, respectively. Functional annotation revealed 119,350 and 150,846 non-redundant protein database annotations (Nr), 96,637 and 115,711 Swiss-Prot annotations, 49,159 and 60,116 Kyoto Encyclopedia of Genes and Genomes annotations (KEGG), and 83,712 and 97,957 Gene Ontology annotations (GO) in S. trilobata and S. calendulacea, respectively. Additionally, our analysis showed that the expression of key protease genes involved in the photosynthesis pathway, particularly CP43, CP47, PsbA and PetC, had high expression levels in leaves of S. trilobata in comparison to native species. Physiological and transcriptomic analyses suggest the high expression of photosynthetic genes ensures the high photosynthetic capacity of leaves, which is one of the inherent advantages underlying the successful invasion by S. trilobata.