Comparative Proteome Analyses Reveal that Nitric Oxide Is an Important Signal Molecule in the Response of Rice to Aluminum Toxicity

Acidic soils inhibit crop yield and reduce grain quality. One of the major contributing factors to acidic soil is the presence of soluble aluminum (Al³⁺) ions, but the mechanisms underlying plant responses to Al³⁺ toxicity remain elusive. Nitric oxide (NO) is an important messenger and participates in various plant physiological responses. Here, we demonstrate that Al³⁺ induced an increase of NO in rice seedlings; adding exogenous NO alleviated the Al³⁺ toxicity related to rice growth and photosynthetic capacity, effects that could be reversed by suppressing NO metabolism. Comparative proteomic analyses successfully identified 92 proteins that showed differential expression after Al³⁺ or NO treatment. In particular, some of the proteins are involved in reactive oxygen species (ROS) and reactive nitrogen species (RNS) metabolism. Further analyses confirmed that NO treatment reduced Al³⁺-induced ROS and RNS toxicities by increasing the activities and protein expression of antioxidant enzymes, as well as <i>S</i>-nitrosoglutathione reductase (GSNOR). Suppressing GSNOR enzymatic activity aggravated Al³⁺ damage to rice and increased the accumulation of RNS. NO treatment altered the expression of proteins associated with cell wall synthesis, cell division and cell structure, calcium signaling and defense responses. On the basis of these results, we propose that NO activates multiple pathways that enhance rice adaptation to Al³⁺ toxicity. Such findings may be applicable to crop engineering to enhance yield and improve stress tolerance

Unique Anatase TiO₂ Twinning Crystals Formed by High-Energy {001} Facets and the Improved Photocatalytic Activity

For the first time, anatase TiO₂ twin crystals have been synthesized by a simple hydrothermal method. The samples are characterized using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, ultraviolet–visible diffused reflectance spectra, and nitrogen sorption isotherms. It is found that a prolonged reaction time significantly contributes to the structure evolution and that twin crystals form via the oriented attachment (OA)- and Ostwald ripening (OR)-controlled secondary growth mechanism. Remarkably, the photoactivity of TiO₂ twin crystals is 2.57 and 8.74 times higher than that of single-crystalline anatase TiO₂ nanosheets and rutile TiO₂, respectively. This has been mainly ascribed to the unique twin crystal structure. This work is a big step toward further improvement of the photocatalytic properties of of TiO₂

Comparative Proteome Analyses Reveal that Nitric Oxide Is an Important Signal Molecule in the Response of Rice to Aluminum Toxicity

Acidic soils inhibit crop yield and reduce grain quality. One of the major contributing factors to acidic soil is the presence of soluble aluminum (Al³⁺) ions, but the mechanisms underlying plant responses to Al³⁺ toxicity remain elusive. Nitric oxide (NO) is an important messenger and participates in various plant physiological responses. Here, we demonstrate that Al³⁺ induced an increase of NO in rice seedlings; adding exogenous NO alleviated the Al³⁺ toxicity related to rice growth and photosynthetic capacity, effects that could be reversed by suppressing NO metabolism. Comparative proteomic analyses successfully identified 92 proteins that showed differential expression after Al³⁺ or NO treatment. In particular, some of the proteins are involved in reactive oxygen species (ROS) and reactive nitrogen species (RNS) metabolism. Further analyses confirmed that NO treatment reduced Al³⁺-induced ROS and RNS toxicities by increasing the activities and protein expression of antioxidant enzymes, as well as <i>S</i>-nitrosoglutathione reductase (GSNOR). Suppressing GSNOR enzymatic activity aggravated Al³⁺ damage to rice and increased the accumulation of RNS. NO treatment altered the expression of proteins associated with cell wall synthesis, cell division and cell structure, calcium signaling and defense responses. On the basis of these results, we propose that NO activates multiple pathways that enhance rice adaptation to Al³⁺ toxicity. Such findings may be applicable to crop engineering to enhance yield and improve stress tolerance

Comparative Proteome Analyses Reveal that Nitric Oxide Is an Important Signal Molecule in the Response of Rice to Aluminum Toxicity

Acidic soils inhibit crop yield and reduce grain quality. One of the major contributing factors to acidic soil is the presence of soluble aluminum (Al³⁺) ions, but the mechanisms underlying plant responses to Al³⁺ toxicity remain elusive. Nitric oxide (NO) is an important messenger and participates in various plant physiological responses. Here, we demonstrate that Al³⁺ induced an increase of NO in rice seedlings; adding exogenous NO alleviated the Al³⁺ toxicity related to rice growth and photosynthetic capacity, effects that could be reversed by suppressing NO metabolism. Comparative proteomic analyses successfully identified 92 proteins that showed differential expression after Al³⁺ or NO treatment. In particular, some of the proteins are involved in reactive oxygen species (ROS) and reactive nitrogen species (RNS) metabolism. Further analyses confirmed that NO treatment reduced Al³⁺-induced ROS and RNS toxicities by increasing the activities and protein expression of antioxidant enzymes, as well as <i>S</i>-nitrosoglutathione reductase (GSNOR). Suppressing GSNOR enzymatic activity aggravated Al³⁺ damage to rice and increased the accumulation of RNS. NO treatment altered the expression of proteins associated with cell wall synthesis, cell division and cell structure, calcium signaling and defense responses. On the basis of these results, we propose that NO activates multiple pathways that enhance rice adaptation to Al³⁺ toxicity. Such findings may be applicable to crop engineering to enhance yield and improve stress tolerance

Comparative Proteome Analyses Reveal that Nitric Oxide Is an Important Signal Molecule in the Response of Rice to Aluminum Toxicity

Acidic soils inhibit crop yield and reduce grain quality. One of the major contributing factors to acidic soil is the presence of soluble aluminum (Al³⁺) ions, but the mechanisms underlying plant responses to Al³⁺ toxicity remain elusive. Nitric oxide (NO) is an important messenger and participates in various plant physiological responses. Here, we demonstrate that Al³⁺ induced an increase of NO in rice seedlings; adding exogenous NO alleviated the Al³⁺ toxicity related to rice growth and photosynthetic capacity, effects that could be reversed by suppressing NO metabolism. Comparative proteomic analyses successfully identified 92 proteins that showed differential expression after Al³⁺ or NO treatment. In particular, some of the proteins are involved in reactive oxygen species (ROS) and reactive nitrogen species (RNS) metabolism. Further analyses confirmed that NO treatment reduced Al³⁺-induced ROS and RNS toxicities by increasing the activities and protein expression of antioxidant enzymes, as well as <i>S</i>-nitrosoglutathione reductase (GSNOR). Suppressing GSNOR enzymatic activity aggravated Al³⁺ damage to rice and increased the accumulation of RNS. NO treatment altered the expression of proteins associated with cell wall synthesis, cell division and cell structure, calcium signaling and defense responses. On the basis of these results, we propose that NO activates multiple pathways that enhance rice adaptation to Al³⁺ toxicity. Such findings may be applicable to crop engineering to enhance yield and improve stress tolerance

Image_2_The bZIP transcription factors in Liriodendron chinense: Genome-wide recognition, characteristics and cold stress response.jpeg

The basic leucine zipper (bZIP) is a transcription factor family that plays critical roles in abiotic and biotic stress responses as well as plant development and growth. A comprehensive genome-wide study in Liriodendron chinense was conducted to identify 45 bZIP transcription factors (LchibZIPs), which were divided into 13 subgroups according the phylogenetic analysis. Proteins in the same subgroup shared similar gene structures and conserved domains, and a total of 20 conserved motifs were revealed in LchibZIP proteins. Gene localization analysis revealed that LchibZIP genes were unequally distributed across 16 chromosomes, and that 4 pairs of tandem and 9 segmental gene duplications existed. Concluding that segmental duplication events may be strongly associated with the amplification of the L. chinense bZIP gene family. We also assessed the collinearity of LchibZIPs between the Arabidopsis and Oryza and showed that the LchibZIP is evolutionarily closer to O. sativa as compared to the A. thaliana. The cis-regulatory element analysis showed that LchibZIPs clustered in one subfamily are involved in several functions. In addition, we gathered novel research suggestions for further exploration of the new roles of LchibZIPs from protein-protein interactions and gene ontology annotations of the LchibZIP proteins. Using the RNA-seq data and qRT-PCR we analyzed the gene expression patterns of LchibZIP genes, and showed that LchibZIP genes regulate cold stress, especially LchibZIP4 and LchibZIP7; and LchibZIP2 and LchibZIP28 which were up-regulated and down-regulated by cold stress, respectively. Studies of genetic engineering and gene function in L. chinense can benefit greatly from the thorough investigation and characterization of the L. chinense bZIP gene family.</p

Image_1_The bZIP transcription factors in Liriodendron chinense: Genome-wide recognition, characteristics and cold stress response.jpeg

The basic leucine zipper (bZIP) is a transcription factor family that plays critical roles in abiotic and biotic stress responses as well as plant development and growth. A comprehensive genome-wide study in Liriodendron chinense was conducted to identify 45 bZIP transcription factors (LchibZIPs), which were divided into 13 subgroups according the phylogenetic analysis. Proteins in the same subgroup shared similar gene structures and conserved domains, and a total of 20 conserved motifs were revealed in LchibZIP proteins. Gene localization analysis revealed that LchibZIP genes were unequally distributed across 16 chromosomes, and that 4 pairs of tandem and 9 segmental gene duplications existed. Concluding that segmental duplication events may be strongly associated with the amplification of the L. chinense bZIP gene family. We also assessed the collinearity of LchibZIPs between the Arabidopsis and Oryza and showed that the LchibZIP is evolutionarily closer to O. sativa as compared to the A. thaliana. The cis-regulatory element analysis showed that LchibZIPs clustered in one subfamily are involved in several functions. In addition, we gathered novel research suggestions for further exploration of the new roles of LchibZIPs from protein-protein interactions and gene ontology annotations of the LchibZIP proteins. Using the RNA-seq data and qRT-PCR we analyzed the gene expression patterns of LchibZIP genes, and showed that LchibZIP genes regulate cold stress, especially LchibZIP4 and LchibZIP7; and LchibZIP2 and LchibZIP28 which were up-regulated and down-regulated by cold stress, respectively. Studies of genetic engineering and gene function in L. chinense can benefit greatly from the thorough investigation and characterization of the L. chinense bZIP gene family.</p

Image_6_CRISPR-mediated genome editing in poplar issued by efficient transformation.tif

BackgroundCRISPR has been increasingly used for plant genetic improvements because of its high efficiency and precision. Recently, the authors have reported the possibility of homology-directed repair (HDR) using CRISPR/Cas9 through woody plants such as poplar. HDR often replaces nucleotides with one donor DNA template (DDT), including homologous sequences.MethodsCRISPR–Cas9 was recruited, and three variables, Agrobacteria inoculator concentration, pDDT/pgRNA ratio, and homologous arm length, were designed to integrate nptII and 2XCamV 35S into the MKK2 promoter zone.ResultsHere, we showed that recovered poplars on kanamycin-supplemented media exhibited enhanced expression of MKK2 affected by the precise integration of 2XcamV 35S and nptII, improving biochemical and phenotypic properties. Our findings confirmed that Agrobacterium inoculator OD600 = 2.5, increased DDT numbers during cell division to 4:1 pDDT/pgRNA, and optimized homologous arms 700 bp caused efficient HDR and increased MKK2 expression.ConclusionEfficient transformations resulted from optimized variables, directly affecting the HDR efficiency through woody plants such as poplar.</p

Table_2_CRISPR-mediated genome editing in poplar issued by efficient transformation.xlsx

BackgroundCRISPR has been increasingly used for plant genetic improvements because of its high efficiency and precision. Recently, the authors have reported the possibility of homology-directed repair (HDR) using CRISPR/Cas9 through woody plants such as poplar. HDR often replaces nucleotides with one donor DNA template (DDT), including homologous sequences.MethodsCRISPR–Cas9 was recruited, and three variables, Agrobacteria inoculator concentration, pDDT/pgRNA ratio, and homologous arm length, were designed to integrate nptII and 2XCamV 35S into the MKK2 promoter zone.ResultsHere, we showed that recovered poplars on kanamycin-supplemented media exhibited enhanced expression of MKK2 affected by the precise integration of 2XcamV 35S and nptII, improving biochemical and phenotypic properties. Our findings confirmed that Agrobacterium inoculator OD600 = 2.5, increased DDT numbers during cell division to 4:1 pDDT/pgRNA, and optimized homologous arms 700 bp caused efficient HDR and increased MKK2 expression.ConclusionEfficient transformations resulted from optimized variables, directly affecting the HDR efficiency through woody plants such as poplar.</p

Polyaniline-Reduced Graphene Oxide Hybrid Nanosheets with Nearly Vertical Orientation Anchoring Palladium Nanoparticles for Highly Active and Stable Electrocatalysis

We report a nearly vertical reduced graphene oxide (VrGO) nanosheet coupled with polyaniline (PANI) for supporting palladium (Pd) nanoparticles. The PANI-coupled VrGO (PANI@VrGO) nanosheet is prepared by a simple one-step electrodeposition technique ,and Pd nanoparticles are anchored on the support of PANI@VrGO through the spontaneous redox reaction of PANI with a palladium salt. The designed PANI@VrGO nanosheet efficiently exposes the surface of rGO sheets and stabilizes metal nanoparticles. Consequently, the Pd/PANI@VrGO electrocatalyst exhibits high catalytic activity and excellent durability for alcohol oxidation reaction. The proposed nanoarchitecture offers a new pathway to greatly promote the performances of rGO in various applications; moreover, this work provides a powerful and universal synthetic strategy for such an architecture