Plant Biotechnology Reports最新文献

The development of an effective and eco-friendly silver nanoparticle (AgNPs) to abate the effect of abiotic stress is an important area of nano-biotechnology. This study aimed to study the priming effect of plant-based green-synthesized silver nanoparticles and melatonin on the physiological and biochemical activities of drought-stressed E. uniflora. Sterilized seeds of E. uniflora were primed with 0.06 mg/l of ML-AgNPs, 0.06 mg/l of melatonin, and a nano-silver formulation of melatonin (1:1). Primed seeds were planted and subjected to 7 days under drought stress. The ML-AgNPs enhanced germination percentage, speed and vigor, and shoot elongation and induced the production of APx, CAT, and proline dehydrogenase (100% increases). Melatonin improved the activities of APx and CAT, total protein, accumulation of proline, and proline dehydrogenase (200% increases) and stabilized MDA content. Meanwhile, silver nano-formulation of melatonin increased leaves proliferation of leaves and production of APx, GPx, SOD, and CAT. Accumulation of proline and 100% upregulation of proline dehydrogenase osmo-regulated the effects of the drought, reduced MDA contents, and stabilized the excessive production of H₂O₂ and O²⁻. The ML-AgNO₃ showed an efficient delivery system of melatonin into the plant under drought stress. As a result, our research shows that melatonin in silver nano-formulation (1:1) is a useful biostimulant against drought stress.

Soybean is one of the richest and cheapest proteins and vegetable oil sources. It is adapted to grow in a varied environment; however, yield loss occurs due to multiple abiotic stresses. Abiotic stresses negatively impact plant growth and development, damaging the crop and decreasing productivity. The last two decades have focused tremendously on improving soybean productivity by dissecting physiological and molecular mechanisms for developing abiotic stress-tolerant varieties. Here, we present a review with a comprehensive outlook on the biotechnological approaches to explore the pathways involved in abiotic stress tolerance in soybean. The review focuses on summarizing transgenic and RNA interference-based strategies as well as genome editing tools to validate the function of abiotic stress-associated genes in soybean. We have also highlighted the significant challenges faced in increasing soybean yield against climatic changes using diverse techniques.

In recent years, there has been significant progress in enhancing the genetic foundation underlying important agricultural traits such as resistance to scab and the development of a columnar growth habit. V. inaequalis is a hemibiotrophic fungus widely distributed in temperate regions where apples are grown on commercial scale. The present investigation was undertaken to identify Vf gene and Co gene, which, respectively, confer resistance against apple scab disease and columnar phenotype in apple cultivar ‘Rosalie’ and introgression of both the genes in commercially important cultivar ‘Fuji’. Polymorphism survey was carried out between the two parents using 22 simple sequence repeat (SSR) and sequence-characterized amplified region (SCAR) markers. The observations revealed that almost 50% hybrids fall in resistant category and 50% in susceptible category. The results of marker-assisted screening confirmed 38 F₁s carrying resistance gene for scab while the remaining 32 F₁ plants were found to be lacking the gene. The 38 genotypically scab-resistant hybrids were selected for further characterization as columnar and non-columnar plants. Based on the selection criteria, 21 individuals were categorized as columnar and the remaining 17 were categorized as non-columnar. The phenotypic screening was followed by screening of F₁ s using molecular markers for Co gene. The amplification of Co-specific markers yielded columnar-specific fragments in the population and fitted the expected 1:1 Mendelian ratio. 18 scab-resistant F₁ hybrids were found to carry Co gene and the remaining 20 did not possess the gene for columnar growth habit. Gene-specific primers identified in the present study can be directly used for screening large apple germplasm in a short period of time for developing resistant varieties against apple scab as well as varieties with columnar growth habit. Hybrids with verified scab resistance and columnar growth can be swiftly utilized as scab-resistant columnar cultivars.

Sorghum is considered a fifth major cereal, widely used as a multipurpose crop worldwide. The use of sorghum as a major forage crop is limited due to cyanogenic glycoside dhurrin in the vegetative shoot tissues. This cyanogenic glycoside is harmful to livestock when fed as fodder. The present study selected three sorghum genotypes for estimating hydrogen cyanide potential (HCNp) in vegetative tissues under well-watered (WW) conditions. The HCNp concentration varied from genotype to genotype and ranged from 364 to 512 ppm. The HCNp estimation was observed more in ICSR 14001 with 511 ppm, followed by ICSV 93046 (443 ppm) and CSH 24 MF (364 ppm). A significant difference was noticed between the genotypes. Sequence information of dhurrin biosynthesis pathway genes was retrieved and characterized using different bioinformatic tools. The gene expression analysis of dhurrin biosynthesis pathway genes showed different expression patterns, with the highest in ICSV 93046 and less in ICSR 14001 and CSH 24 MF. Genes CYP79A1, CYP71E1 and UGT85B1 showed a 2.5- to 4 fold increase in ICSV 93046 and no significant expression in ICSR 14001 and CSH 24 MF. The genotype CSH 24 MF observed a 1.5-fold increase in CYP79A1 gene expression, and the other genes observed no significant increase. This study assisted in identifying the contrasting genotypes inducing HCNp and the key genes of the dhurrin pathway producing hydrogen cyanide (HCN) under WW conditions, which can be used as potential candidates for gene editing, providing safe feed for the livestock.

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides that lack significant protein coding potential and have been shown to regulate various biological processes. This study was designed to identify lncRNAs in coconut and their role in the process of somatic embryogenesis in coconut, a crop with high recalcitrance to in vitro culture. RNA-Seq data of coconut embryogenic calli of the West Coast Tall cultivar was exploited for in silico prediction of lncRNA. From a total of 6328 transcripts, which were annotated as uncharacterised or with no homology hits with the existing database, 5110 putative lncRNAs are identified. We also studied the relationship between lncRNAs, microRNAs (miRNAs) and mRNAs and found that some of the lncRNAs act as miRNA precursors, some as potential miRNA targets and some function as endogenous target mimics (eTMs) for miRNAs. Real-time quantitative PCR confirmed that 10 selected lncRNAs showed significant differences in the expression pattern in different stages of coconut somatic embryogenesis. Our results suggest the existence of diverse lncRNAs in coconut embryogenic calli, some of which are differentially expressed. The information generated in this study could be of great value in understanding the molecular mechanisms governing somatic embryogenesis in coconut.

Abstract

Expansin plays a crucial role in plant growth and stress resistance as a cell wall relaxation protein. The expansin family consists of four subfamilies: EXPA, EXPB, EXLA, and EXLB. However, a few reports have been previously published investigating EXLA genes. The research here aimed to characterize the PtEXLA1 gene from a popular species (P. alba × P. glandulosa CV.84K) and evaluate its role through genetic transformation to understand its contribution to plant growth and stress resistance. The results showed that the PtEXLA1 gene was 780 bp in length, encoded 259 amino acids, and had typical characteristics of EXLA. The PtEXLA1 transgenic tobacco plants had a larger corolla in comparison to wild-type plants, and exhibited higher resistance to drought, high temperature, and salt stress based on the evaluation of chlorophyll content, relative conductivity, and malondialdehyde content. PtEXLA1 can be an efficient gene resource for stress resistance breeding of plants.

The ATP-binding cassette (ABC) transporter family is one of the largest protein families in plants and plays an essential role in addressing biotic and abiotic stresses. Wheat, a vital global grain crop, faces multifaceted safety challenges, primarily from fungal diseases like stripe rust and powdery mildew. In the present study, we identified the whole genome of the wheat ABC family, and 463 nonredundant ABC genes were identified. The ABC family can be divided into nine evolutionary branches and eight subfamilies based on phylogenetic tree analysis. This paper delved deeper into characterizing the gene structure, promoter region, and gene expression within the TaABC family. Segmental duplication was the main reason for the expansion of the TaABC genes. Ka/Ks analysis suggested that most TaABC genes were intensely purified and selected. The collinear analysis of TaABC and other species showed that the ABC genes were conserved in evolution. RNA-seq data and qPCR data from wheat infected with powdery mildew or stripe rust showed that most TaABC genes were induced to change expression. The candidate genes TaABCB15-3B and TaABCG38 exhibited responsiveness to powdery mildew in resistant/susceptible wheat, while remaining unresponsive to stripe rust. Our findings serve as a valuable reference for gaining a deeper understanding of the function and evolution of TaABCs, aiding in the identification of enduring disease resistance genes within the TaABCs of wheat.

The performance of crop plants is critically affected by biotic and abiotic stress. These stressors threaten food availability by reducing overall crop yield and productivity. Changes in chromatin state by epigenetic modification are part of plant adaptive and survival responses and are considered pivotal for improving agronomic traits. Epigenetics is an exciting field that involves heritable gene expression changes that do not require changes in DNA sequence. Epigenetic modification is well known as a crucial player in plant phenotypic diversity and defense against pathogens. Hence, there is a growing interest in unlocking the epigenome for crop improvement. Herein, we highlight the epigenetic modifications implicated in plant biotic stress response and their contributions to important agronomic traits. We also discussed adopting epigenetics to expand phenotypic diversity and produce desired characteristics in crop plants.

Floral architecture plays a pivotal role in developmental processes under genetic regulation and is also influenced by environmental cues. This affects the plant silique phenotype in Arabidopsis and grain yield in crops. Despite the relatively small number of family members of zinc finger homeodomain (ZF-HD) transcription factors (TFs) in plants, their biological role needs to be investigated to understand the molecular mechanisms associated with plant developmental processes. Therefore, we generated HB31SRDX and HB21SRDX repressor mutant lines to understand the functional role of ZF-HD TFs. The mutant lines showed severe defects in plant architecture, including increased branching number, reduced plant height, distorted floral phenotype, and short silique. We found that HB31 and HB21 are paralogs in Arabidopsis, and both positively regulate cell size-related genes, cell wall modification factor-related genes, and M-type MADS-box TF families. In addition, HB31 and HB21 are negatively associated with abiotic stress-related genes, vegetative-to-reproductive phase transition of meristem-related genes, and TCP and RAV TFs. microRNA164 (miR164), miR822, miR396, miR2934, and miR172 were downregulated, whereas miR169, miR398, miR399, and miR157 were upregulated in the two repressor lines. Phenotypic and molecular analyses demonstrated that the miR396/GRF modules regulated by HB31 and HB21 are involved in the plan floral architecture of Arabidopsis. The findings of this study will help elucidate the role of ZF-HD TFs in maintaining the floral architecture.

Pesticides have been an integral part of modern agriculture as their use ensures good harvests. However, excessive use of pesticides in the last few decades has caused significant environmental degradation. Moreover, excessive use of pesticides causes stress on crops and non-target plants and exhibits toxicity to other organisms including mammals, microbes, and insects. Plants employ various morphological, physiological, and biochemical mechanisms to reduce pesticides toxicity. One such mechanism is production of secondary metabolites that improves stress tolerance of plants. In addition, recent studies have also highlighted a potential role of plasma technology in mitigating various abiotic and biotic environmental stresses. Besides, plasma treatment improves seed germination, physiological processes, and seedling establishment during the early growth stages of a plant under adverse and non-adverse conditions and thus can be used an alternate to the pesticide treatment. This review article summarizes recent advancements in understanding the synthesis, accumulation, and transportation of secondary metabolites which have significant relevance to crop improvement programs. We also present an overview of the effects of plasma treatment on phytopathogenic bacterial cell suspensions and plant responses to metabolic activity. In the future, researchers need to develop innovative ideas to reduce the use of chemical pesticides in farming practices.