ResearchPad - photosynthesis-and-metabolism https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Thioredoxin targets are regulated in heterocysts of cyanobacterium <i>Anabaena</i> sp. PCC 7120 in a light-independent manner]]> https://www.researchpad.co/article/elastic_article_10047 In phototrophs, thioredoxin targets are generally reduced in a light-dependent manner. In contrast, thioredoxin targets in heterocysts of nitrogen-fixing cyanobacteria are regulated independently of light conditions.

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<![CDATA[Lethality caused by ADP-glucose accumulation is suppressed by salt-induced carbon flux redirection in cyanobacteria]]> https://www.researchpad.co/article/elastic_article_10045 Cyanobacteria are widely distributed photosynthetic organisms. During the day they store carbon, mainly as glycogen, to provide the energy and carbon source they require for maintenance during the night. Here, we generate a mutant strain of the freshwater cyanobacterium Synechocystis sp. PCC 6803 lacking both glycogen synthases. This mutant has a lethal phenotype due to massive accumulation of ADP-glucose, the substrate of glycogen synthases. This accumulation leads to alterations in its photosynthetic capacity and a dramatic decrease in the adenylate energy charge of the cell to values as low as 0.1. Lack of ADP-glucose pyrophosphorylase, the enzyme responsible for ADP-glucose synthesis, or reintroduction of any of the glycogen synthases abolishes the lethal phenotype. Viability of the glycogen synthase mutant is also fully recovered in NaCl-supplemented medium, which redirects the surplus of ADP-glucose to synthesize the osmolite glucosylglycerol. This alternative metabolic sink also suppresses phenotypes associated with the defective response to nitrogen deprivation characteristic of glycogen-less mutants, restoring the capacity to degrade phycobiliproteins. Thus, our system is an excellent example of how inadequate management of the adenine nucleotide pools results in a lethal phenotype, and the influence of metabolic carbon flux in cell viability and fitness.

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<![CDATA[Final grain weight is not limited by the activity of key starch-synthesising enzymes during grain filling in wheat]]> https://www.researchpad.co/article/5c19b244d5eed0c484c4fb54

In field conditions that favour high yields, final grain weight of wheat is not limited by sugar availability or activities of key enzymes of starch synthesis during grain filling.

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<![CDATA[A novel glycosyltransferase catalyses the transfer of glucose to glucosylated anthocyanins in purple sweet potato]]> https://www.researchpad.co/article/5c19b243d5eed0c484c4fb02

Sweet potato Ib3GGT catalyses anthocyanidin 3-O-glucosides into anthocyanidin 3-O-sophorosides using UDP-glucose as the sugar donor, and Thr-138 is the key residue that determines the sugar-donor specificity of the cytosolic enzyme.

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<![CDATA[Spatially resolved metabolic analysis reveals a central role for transcriptional control in carbon allocation to wood]]> https://www.researchpad.co/article/5b694a88463d7e394646944f

Central primary metabolism enzyme activities track transcript abundance during secondary cell wall formation in wood.

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<![CDATA[Phenotyping of field-grown wheat in the UK highlights contribution of light response of photosynthesis and flag leaf longevity to grain yield]]> https://www.researchpad.co/article/5c08335cd5eed0c484f99aa0

Flag leaf longevity and operating photosynthetic rates at ambient CO2 and a range of light levels correlated with grain yield of UK field-grown wheat, revealing new targets to enhance crop productivity.

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<![CDATA[Jasmonate-responsive MYB factors spatially repress rutin biosynthesis in Fagopyrum tataricum]]> https://www.researchpad.co/article/5c07a1a1d5eed0c484e011bc

Jasmonate-responsive repressors of FtMYBs can be degraded by the 26S proteasome in a COI1-dependent manner in Fagopyrum tataricum and act together with FtSAD2 or FtJAZ1 in the phenylpropanoid pathway.

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<![CDATA[Direct measurement of intercellular CO2 concentration in a gas-exchange system resolves overestimation using the standard method]]> https://www.researchpad.co/article/5c07a1a7d5eed0c484e01313

Obtaining leaf intercellular CO2 concentration by direct measurement, which is affected by neither cuticle properties nor stomatal behavior, is better than by calculation, which largely neglects cuticular gas transport when stomatal gas transport is restricted

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