Glu receptors are known to function as Glu-activated ion channels that mediate mostly excitatory neurotransmission in animals. Glu receptor–like genes have also been reported in higher plants, although their function is largely unknown. We have identified a rice (Oryza sativa) Glu receptor–like gene, designated GLR3.1, in which mutation by T-DNA insertion caused a short-root mutant phenotype. Histology and DNA synthesis analyses revealed that the mutant root meristematic activity is distorted and is accompanied by enhanced programmed cell death. Our results supply genetic evidence that a plant Glu receptor–like gene, rice GLR3.1, is essential for the maintenance of cell division and individual cell survival in the root apical meristem at the early seedling stage.

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Gracilariopsis lemaneiformis (aka Gracilaria lemaneiformis) is a red macroalga rich in phycoerythrin, which can capture light efficiently and transfer it to photosystemⅡ. However, little is known about the synthesis of optically active phycoerythrinin in G. lemaneiformis at the molecular level. With the advent of high-throughput sequencing technology, analysis of genetic information for G. lemaneiformis by transcriptome sequencing is an effective means to get a deeper insight into the molecular mechanism of phycoerythrin synthesis. Illumina technology was employed to sequence the transcriptome of two strains of G. lemaneiformis- the wild type and a green-pigmented mutant. We obtained a total of 86915 assembled unigenes as a reference gene set, and 42884 unigenes were annotated in at least one public database. Taking the above transcriptome sequencing as a reference gene set, 4041 differentially expressed genes were screened to analyze and compare the gene expression profiles of the wild type and green mutant. By GO and KEGG pathway analysis, we concluded that three factors, including a reduction in the expression level of apo-phycoerythrin, an increase of chlorophyll light-harvesting complex synthesis, and reduction of phycoerythrobilin by competitive inhibition, caused the reduction of optically active phycoerythrin in the green-pigmented mutant.

Organic phosphates (OP) account for approximately 30–90% of total soil P. However, it is too stable to be utilized by plants as available P source. Aspergillus niger (A. niger) has considerable ability to secret phytase to decompose OP. Meanwhile, mineralization of lead (Pb) is efficient to achieve its remediation. This study hence investigated Pb immobilization by A. niger assisted decomposition of OP under variable acidic environments. A. niger can survive in the acidic environment as low as pH = 1.5. However, alternation of environmental pH within 3.5–6.5 significantly changed fungal phytase secretion. In particular, weakly acidic stimulation (pH of ~5.5) increased phytase activity secreted by A. niger to 0.075 µmol/min/mL, hence elevating P release to a maximal concentration of ~20 mg/L. After Pb addition, ATR-IR and TEM results demonstrated the formation of abundant chloropyromorphite [Pb5(PO4)3Cl] mineral on the surface of mycelium at pH = 5.5. Anglesite, with a higher solubility than pyromorphite, was precipitated massively in other treatments with pH lower or higher than 5.5. This study elucidated the great potential of applying OP for Pb immobilization in contaminated water.

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This study provides a better understanding of nitrate regulation in H. pluvialis.

Fungi play a significant role in biological corrosion of metal materials. We studied the biocorrosion of lead foils under incubation of Aspergillus niger (A. niger). Multiple techniques, for example, scanning electron microscopy (SEM), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), and Raman imaging and scanning electron microscopy (RISE), were applied in this study. SEM confirmed the normal growth of the fungus on Pb foil surface, either above or under the solid medium surface. In addition, SEM‐energy dispersive spectrometer confirmed the formation of the secondary Pb mineral particles after incubation, which had variable morphologies. DRIFT was able to show changes of compounds formed on the surface of Pb foils. However, it cannot exactly identify the mineral phase. RISE technology offered both morphological and spectral information of the formed Pb mineral. Three dominant Raman peaks at ~1,440, ~1,480, and ~1,590 cm−1 indicated that the secondary mineral was lead oxalate. Raman mapping further demonstrated the distribution of Pb oxalate architecture. This study first applied RISE to investigate the biocorrosion of metals by fungi.