Journal of Plant Biochemistry and Biotechnology最新文献

Abstract

Identifying and characterizing genes that control important agronomic traits and finding ways to alter them are vital for crop improvement. Map-based cloning, heterologous gene expression, RNAi mediated gene silencing, T-DNA insertional mutation and TILLING technologies have enabled cloning, characterization, and deployment of a few important genes. Revolution in sequencing technologies and bioinformatics has facilitated us to quickly predict and annotate plethora of genes and regulatory elements with improved precision and spatio-temporal expression of genes in almost all cereal crops. However, their functional validation forms a bottleneck in exploiting useful genetic elements for crop improvement. The CRISPR/Cas9 mediated gene editing has become the tool of choice for precisely introducing targeted modifications in the genome to knock out/in a gene, introducing specific mutation in sequence or modulating its expression in diverse crop species. This can help to rapidly characterize plenty of genes in terms of understanding the function of individual gene/ gene family, involvement in a particular biochemical pathway or interaction of the crop plant with external stimuli at a reasonable cost. In this review, we discuss the power of gene editing for rapid functional characterization of genetic elements as a fundamental requirement to harness the power of precision genetic technologies for increasing crop yield, progress made so far, opportunities and challenges.

Salinity is one of the major environmental factors that limit the plant growth and crop productivity worldwide. Tonoplast Na⁺/H⁺ transporters (NHXs) play crucial roles in regulating the intracellular Na⁺/K⁺ and pH homoeostasis, which is essential for salt tolerance and development of plants. In the present study, a novel gene BvNHX1 encoding tonoplast Na⁺/H⁺ antiporter was isolated in natrophilic crop sugar beet (Beta vulgaris) and functionally characterized in tobacco (Nicotiana tabacum) plants to assess the behavior of the transgenic organisms in the response to salt stress. The results showed that overexpression of BvNHX1 significantly enhanced salt tolerance in transgenic tobacco plants compared with wild-type (WT) plants. The seed germination, root length, plant height, and fresh and dry weights in transgenic plants were significantly higher than those in WT plants under salt stresses. The contents of leaf relative water, chlorophyll, proline, soluble sugars, and soluble proteins were significantly higher as compared with WT plants, while malondialdehyde (MDA) contents were significantly lower than those of WT plants under salt stresses. Na⁺ and K⁺ contents both in shoots and roots of transgenic plants were significantly higher than those of WT plants, and transgenic plants maintained a balanced K⁺/Na⁺ ratio under saline conditions. Taken together, these results suggested that overexpression of BvNHX1 reduced damage to cell membrane by reducing osmotic potential of cells, and maintaining relative water and chlorophyll contents of leaves, and finally improved salt tolerance in transgenic tobacco plants.

MYB44 played key roles in plant responses to abiotic and biotic stress and important roles in plant metabolism and development. At present, the function of MYB44 has not been systemically summarized in plants. In this review, we systemically summarized the structure and function of MYB44 in plants, such as how MYB44 interplays in phytohormone signaling pathways; how MYB44 regulates abiotic and biotic stress, which includes drought tolerance, salt tolerance, cold tolerance, responding to phosphate and nitrogen starvation, and disease resistance; and how MYB44 regulates plant metabolism, which contains MYB44 regulates fruit malate accumulation, starch biosynthesis, sucrose accumulation, flavonoid accumulation, anthocyanin biosynthesis, chlorophyll degradation, and leaf senescence; it also regulates plant development, which includes root growth and development and somatic embryogenesis in plants. Moreover, we constructed the regulatory networks of the MYB44 protein's responses to biotic and abiotic stress and their regulation of plant metabolism and development. Furthermore, we give some suggestions on how to use MYB44 as a positive and negative regulator to create new breeds in the future.

Drought stress has been known to adversely affect growth, development, and productivity of plants to varying extent. Being a multifaceted trait, drought tolerance involves interaction of an array of genes, pathways, and mechanisms. A unique regulatory scheme is adopted by different plants, which provides tolerance to drought stress in association with biochemical and physiological mechanisms. Transcriptome analysis of a drought tolerant [Nagina 22 (N-22)] and drought sensitive (IR-64) cultivars provides insights into the genes/pathways/mechanisms involved in terminal drought stress tolerance. In the present study, comparative physio-biochemical analyses of the rice cultivars under terminal drought stress substantiated their performance. Whole transcriptome analysis of leaf and root from the rice cultivars exposed to terminal drought stress revealed 6077 and 10,050 differentially expressed genes (DEGs) in leaf of N-22 and IR-64, respectively, under drought stress. A maximum of 2682 genes were up-regulated exclusively in N-22 while 7198 genes were down-regulated exclusively in leaf of IR-64. Interestingly, the highest number (2594) of genes was down-regulated exclusively in roots of IR-64, while only 1497 gene were up-regulated exclusively in root of N-22. Differential expression of OsNAC10, OsbZIP23, OsABA8ox1, OsCPK4, OsLEA3, and OsNCED4 along with the GO terms enriched with up-regulated genes for transcription factors (TFs), redox homeostasis, and ABA signaling in N-22 under terminal drought stress play crucial roles in stress tolerance. The stress-responsive genes for transcription factors, redox homeostasis, and ABA signaling up-regulated in N-22 were mainly responsible for terminal drought tolerance. These stress-associated genes can be utilized for genetic improvement of rice for drought tolerance.

The creators of CRISPR/Cas have been awarded the 2020 Nobel Prize in Chemistry for their ground-breaking technology and its exceptional potential to address fundamental issues in the field of biological sciences. This revolutionary tool has accelerated the development of novel crop varieties with enhanced features in agriculture, all without the need for transgenes. However, in order for this technology to reach its full potential, the establishment of a precise and comprehensive global regulatory framework for these crops is crucial. Despite the absence of foreign genetic material in crops developed through CRISPR/Cas mediated genome editing, there is an ongoing and intense debate surrounding the regulation of these crops prior to their release into the market. While certain CRISPR-edited crops have already been introduced in Japan, their legal status remains a point of contention in several nations, including the EU and New Zealand. This review paper serves as a comprehensive guide to the worldwide regulatory framework for CRISPR-edited crops, as well as provide insights into the future prospects of this transformative technology. By examining the current landscape of regulations and exploring potential avenues for harmonization, we can better understand the challenges and opportunities that lie ahead for CRISPR-edited crops.

Genome or gene editing (GE) involves a repertoire of innovative molecular techniques that make use of sequence-specific nucleases (SSNs), for the precise modification of an organism's genome sequences. The CRISPR/Cas-based GE system, associated with Clustered Regularly Interspaced Short Palindromic Repeats, has emerged as a potent addition to the expanding genomics toolkit. It enables precise mutagenesis, gene knockouts, multiplex gene editing, and the manipulation of gene expression in plants. Undoubtedly, the application of CRISPR/Cas-based GE in plants has brought about a revolution in basic research, aiding in our understanding of gene functions and significantly advancing applied crop research. This, in turn, underscores its immense potential for crop improvement. Against this backdrop, the current Special Issue on "Genome Editing in Plants: A Tool for Precision Breeding and Functional Genomics" represents a timely effort to assemble a group of leading experts in the field of plant genome editing. This compilation includes a commentary article, two original research papers, and eleven review articles and is expected to bring about substantial progress in the field of plant science, particularly in the domain of genome editing.

Gene editing using the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9 (CRISPR/Cas9) system has become an important biotechnological tool for studying gene function and improving crops. In the present study, the potential of the system was assessed for squash (Cucurbita pepo subspecies pepo) by targeting phytoene desaturase (PDS) gene using the particle bombardment method. The recombinant pHSE401 vector, carrying two sgRNAs (gRNA1 and gRNA2) specific to the PDS homolog (Cp4.1LG08g06310, CpPDS) under the control of Arabidopsis U6 promoter and the Cas9 protein was developed and bombarded into cotyledonary node explants of squash cv. Black Beauty. The transformation efficiency of 4.5% was observed and all the transformants exhibited albino/bleached phenotype. The CpPDS knockout system generated easily detectable bleached/albino explants within 6–8 weeks. The albino phenotype was confirmed through Sanger sequencing which detected several deletion mutations (single, two and three bp deletion) within the CpPDS-gRNA1 target. However, no mutations were found within the CpPDS-gRNA2 target. This study demonstrated CRISPR/Cas9 as a viable tool for gene editing in squash and provides a platform for the modification of economically important traits in the crop.

To identify putative antimitotic compounds, the pseudostem of banana plant (PSBP) was chosen and assays were carried out with aqueous extract of PSBP. Aqueous extract of PSBP decreased the mitotic index in onion root tips. Moreover, this extract inhibited the regeneration of blastema in amputated earthworms. Validation of this extract with MTT (3-(4, 5-dimethyl thiazolyl-2-yl)—2, 5-diphenyltetrazolium bromide) assay using MCF-7 human breast cancer cell line confirmed the presence of antimitotic activity. LC–MS analysis of this extract revealed the presence of three potential antimitotic compounds viz. α-tocotrienoxyl radical (ATT), 1,2,4-nonadecanetriol (NAT), and 3′,4′,7-trihydroxyisoflavone (THIF). Molecular docking studies suggested that these three compounds associate with α- and β-tubulin of mammalian cells and might have influenced the polymerization of microtubules. Besides, these compounds bind with active sites of cyclin-dependent kinase 2 (CDK2) protein which is required for cell division. Molecular dynamics (MD) simulation studies indicated the strong binding of THIF with α-tubulin, whereas ATT and NAT ligands with CDK2 protein. Our results clearly indicated the presence of three different antimitotic compounds from new resource and inhibit mitotic cell division. Pseudostem of banana plants could be an excellent resource for production of commercially significant antimitotic compounds.