Physiology and Molecular Biology of Plants最新文献

Content of bioactive constituents is one of the most important characteristics in Rheum palmatum complex. Increasing ingredient content through genetic breeding is an effective strategy to solve the contradiction between large market demand and resource depletion, but currently hampered by limited understanding of metabolite biosynthesis in rhubarb. In this study, deep transcriptome sequencing was performed to compare roots, stems, and leaves of two Rheum species (PL and ZK) that show different levels of anthraquinone contents. Approximately 0.52 billion clean reads were assembled into 58,782 unigenes, of which around 80% (46,550) were found to be functionally annotated in public databases. Expression patterns of differential unigenes between PL and ZK were thoroughly investigated in different tissues. This led to the identification of various differentially expressed genes (DEGs) involved in shikimate, MEP, MVA, and polyketide pathways, as well as those involved in catechin and gallic acid biosynthesis. Some structural enzyme genes were shown to be significantly up-regulated in roots of ZK with high anthraquinone content, implying potential central roles in anthraquinone synthesis. Taken together, our study provides insights for future functional studies to unravel the mechanisms underlying metabolite biosynthesis in rhubarb.

Fagopyrum tataricum, an important medicinal and edible crop, possesses significant agricultural and economic value. However, the development of buckwheat varieties and yields has been hindered by the delayed breeding progress despite the abundant material resources in China. Current research indicates that quantitative trait loci (QTLs) play a crucial role in controlling plant seed type and yield. To address these limitations, this study constructed recombinant inbred lines (RILs) utilizing both cultivated species and wild buckwheat as raw materials. In total, 84,521 Single Nucleotide Polymorphism (SNP) markers were identified through Genotyping-by-Sequencing (GBS) technology, and high-resolution and high-density SNP genetic maps were developed, which had significant value for QTL mapping, gene cloning and comparative mapping of buckwheat. In this study, we successfully identified 5 QTLs related to thousand grain weight (TGW), 9 for grain length (GL), and 1 for grain width (GW) by combining seed type and TGW data from 202 RIL populations in four different environments, within which one co-located QTL for TGW were discovered on the first chromosome. Transcriptome analysis during different grain development stages revealed 59 significant expression differences between the two materials, which can serve as candidate genes for further investigation into the regulation of grain weight and yield enhancement. The mapped major loci controlling TGW, GL and GW will be valuable for gene cloning and reveal the mechanism underlying grain development and marker-assisted selection in Tartary buckwheat.

Mints are aromatic plants of Lamiaceae, globally known for the phytochemical-rich essential oils. Most of the cultivated mints are menthol-rich, whereas spearmint being the only dominant carvone-rich species. In this study, another carvone-rich mint Mentha rotundifolia (L.) Huds., a native of temperate region was assessed for its acclimation in sub-tropical environment to see any possible changes in specialized metabolite accumulation. Plants grown under open environment was compared with glasshouse grown plants where, temperature, humidity and photoperiods were uniformly maintained. Thickened leaves with increased cuticular wax load (2.82 folds) and anthocyanin accumulation (202.97 µg/g) in the widened stems were observed in plants grown in open environment, while higher chlorophyll contents were exhibited by the glasshouse-grown plants. Enhanced antioxidant capacity in open environment, correlated with elevated concentration (86.4% increase for caffeic acid) of wall-bound phenolics was observed. Increased proline, hydrogen peroxide and malondialdehyde contents in open environment indicated the plant’s ability to cope up with abiotic stress. Higher amounts of terpenes like (-)-carvone (2.68 folds) and D-limonene (1.35 folds) were found in both internal volatile pool and essential oil of glasshouse-grown plants. Histochemical study of glandular trichomes also supported this finding. In conclusion, glasshouse-grown plants showed relatively better growth and higher terpene contents, nevertheless the plant survived well in warmer environment, with increased antioxidant capacities and phenolic contents. Future study includes mass propagation of this species in different geographical locations with distinct climatic variations to determine the suitable sub-tropical locations for cultivation as a potential alternative to spearmint for commercial-scale (-)-carvone production.

The global CO₂ concentration is predicted to reach 700 µmol·mol⁻¹ by the end of this century. Phoebe bournei (Hemsl.) Yang is a precious timber species and is listed as a national secondary protection plant in China. P. bournei seedlings show obvious photosynthetic decline when grown long-term under an elevated CO₂ concentration (eCO₂, EC). This decline can be alleviated by high nitrate or ammonium applications. However, the underlying mechanisms have not yet been elucidated. We performed transcriptomic and proteomic analyses of P. bournei of seedlings grown under an ambient CO₂ concentration (AC) and applied with either a moderate level of nitrate (N), a high level of nitrate (hN), or a moderate level of ammonium (A) and compared them with those of seedlings grown under eCO₂ (i.e., AC_N vs EC_N, AC_hN vs EC_hN, AC_A vs EC_A) to identify differentially expressed genes (DEGs) and differentially expressed proteins (DEPs). We identified 4528 (AC_N vs EC_N), 1378 (AC_hN vs EC_hN), and 252 (AC_A vs EC_A) DEGs and 230, 514, and 234 DEPs, respectively, of which 59 specific genes and 21 specific proteins were related to the regulation of photosynthesis by nitrogen under eCO₂. A combined transcriptomic and proteomic analysis identified 7 correlation-DEGs-DEPs genes. These correlation-DEGs-DEPs genes revealed crucial pathways involved in glyoxylate and dicarboxylate metabolism and nitrogen metabolism. The rbcS and glnA correlation-DEGs-DEPs genes were enriched in these two metabolisms. We propose that the rbcS and glnA correlation-DEGs-DEPs genes play an important role in photosynthetic decline and nitrogen regulation. High nitrate or ammonium applications alleviated the downregulation of glnA and rbcS and, hence, alleviated photosynthetic decline. The results of this study provide directions for the screening of germplasm resources and molecular breeding of P. bournei, which is tolerant to elevated CO₂ concentrations.

Nitrogen is an essential macronutrient critical for plant growth and productivity. Plants have the capacity to uptake inorganic nitrate and ammonium, with nitrate playing a crucial role as a signaling molecule in various cellular processes. The availability of nitrate and the signaling pathways involved finely tune the processes of nitrate uptake and assimilation. NIN-like proteins (NLPs), a group of transcription factors belonging to the RWP-RK gene family, act as major nitrate sensors and are implicated in the primary nitrate response (PNR) within the nucleus of both non-leguminous and leguminous plants through their RWP-RK domains. In leguminous plants, NLPs are indispensable for the initiation and development of nitrogen-fixing nodules in symbiosis with rhizobia. Moreover, NLPs play pivotal roles in plant responses to abiotic stresses, including drought and cold. Recent studies have identified NLP homologs in oomycete pathogens, suggesting their potential involvement in pathogenesis and virulence. This review article delves into the conservation of RWP-RK genes, examining their significance and implications across different plant species. The focus lies on the role of NLPs as nitrate sensors, investigating their involvement in various processes, including rhizobial symbiosis in both leguminous and non-leguminous plants. Additionally, the multifaceted functions of NLPs in abiotic stress responses, developmental processes, and interactions with plant pathogens are explored. By comprehensively analyzing the role of NLPs in nitrate signaling and their broader implications for plant growth and development, this review sheds light on the intricate mechanisms underlying nitrogen sensing and signaling in various plant lineages.

Plants maintain cellular homeostasis of phosphate (Pi) through an integrated response pathway regulated by different families of transcription factors including MYB, WRKY, BHLH, and ZFP. The systemic response to Pi limitation showed the critical role played by inositol pyrophosphate (PP-InsPs) as signaling molecule and SPX (SYG1/PHO81/XPR1) domain proteins as sensor of cellular Pi status. Binding of SPX to PP-InsPs regulates the transcriptional activity of the MYB-CC proteins, phosphate starvation response factors (PHR/PHL) as the central regulator of Pi-deficiency response in plants. Vacuolar phosphate transporter, VPT may sense the cellular Pi status by its SPX domain, and vacuolar sequestration is activated under Pi replete condition and the stored Pi is an important resource to be mobilized under Pi deficiency. Proteomic approaches led to new discoveries of proteins associated with Pi-deficient response pathways and post-translational events that may influence plants in achieving Pi homeostasis. This review provides current understanding on the molecular mechanisms at the transcriptional and translational levels for achieving Pi homeostasis in plants. The potential strategies for employing the CRISPR technology to modify the gene sequences of key regulatory and response proteins for attaining plant Pi homeostasis are discussed.

Grain weight (GW) is the most important stable trait that directly contributes to crop yield in case of cereals. A total of 105 backcross introgression lines (BC₂F₁₀ BILs) derived from Swarna/O. nivara IRGC81848 (NPS) and 90 BILs from Swarna/O. nivara IRGC81832 (NPK) were evaluated for thousand-grain weight (TGW) across four years (wet seasons 2014, 2015, 2016 and 2018) and chromosome segment substitution lines (CSSLs) were selected. From significant pair- wise mean comparison with Swarna, a total of 77 positively and 29 negatively significant NPS lines and 62 positively and 29 negatively significant NPK lines were identified. In all 4 years, 14 NPS lines and 9 NPK lines were positively significant and one-line NPS69 (IET22161) was negatively significant for TGW over Swarna consistently. NPS lines and NPK lines were genotyped using 111 and 140 polymorphic SSRs respectively. Quantitative trait locus (QTL) mapping using ICIM v4.2 software showed 13 QTLs for TGW in NPS. Three major effect QTLs qTGW2.1, qTGW8.1 and qTGW11.1 were identified in NPS for two or more years with PVE ranging from 8 to 14%. Likewise, 10 QTLs were identified in NPK and including two major effect QTL qTGW3.1 and qTGW12.1 with 6 to 32% PVE. In all QTLs, O. nivara alleles increased TGW. These consistent QTLs are very suitable for fine mapping and functional analysis of grain weight. Further in this study, CSSLs NPS1 (10-2S) and NPK61 (158 K) with significantly higher grain weight than the recurrent parent, Swarna cv. Oryza sativa were selected from each population and secondary F₂ mapping populations were developed. Using Bulked Segregant QTL sequencing, a grain weight QTL, designated as qTGW3.1 was fine mapped from the cross between NPK61 and Swarna. This QTL explained 48% (logarithm of odds = 32.2) of the phenotypic variations and was fine mapped to a 31 kb interval using recombinant analysis. GRAS transcription factor gene (OS03go103400) involved in plant growth and development located at this genomic locus might be the candidate gene for qTGW3.1. The results of this study will help in further functional studies and improving the knowledge related to the molecular mechanism of grain weight in Oryza and lays a solid foundation for the breeding for high yield.

Fall Armyworm imposes a major risk to agricultural losses. Insecticides have historically been used to manage its infestations, but it eventually becomes resistant to them. To combat the pest, a more recent strategy based on the use of transgenic maize that expresses Bt proteins such as Cry1F from the bacteria has been used. Nonetheless, there have been numerous reports of Cry1F maize resistance in FAW populations. Nowadays, the more effective and less time-consuming genome editing method known as CRISPR/Cas9 technology has gradually supplanted these various breeding techniques. This method successfully edits the genomes of various insects, including Spodoptera frugiperda. On the other hand, this new technique can change an insect’s DNA to overcome its tolerance to specific insecticides or to generate a gene drive. The production of plant cultivars resistant to fall armyworms holds great potential for the sustainable management of this pest, given the swift advancement of CRISPR/Cas9 technology and its varied uses. Thus, this review article discussed and critically assessed the use of CRISPR/Cas9 genome-editing technology in long-term fall armyworm pest management. However, this review study focuses primarily on the mechanism of the CRISPR-Cas9 system in both crop plants and insects for FAW management.

Bacopa monnieri L. is a highly acclaimed plant species for its diverse pharmaceutical properties and is mostly found in the Indian subcontinent. In this study, the effects of salt (KCl) stress on plant height, biomass, chlorophyll content, and antioxidant enzyme activities of Bacopa monnieri in both in vitro and in vivo conditions were investigated. A significant increase of up to 1.8 folds and 1.3 folds in bacoside-A content at 100 mM KCl was recorded in both in vivo and in vitro grown plants, respectively. Higher salinity (> 100 mM KCl) stress exerted a negative effect on plant height and plant biomass, whereas at levels ≤ 100 KCl, substantial improvement in terms of plant height (PH) and biomass (PB) was recorded in both in vivo (up to 1.6-fold and 1.8-fold high) and in vitro (up to 1.9-fold and 1.7-fold high) conditions. Total chlorophyll content and antioxidant enzyme (CAT, POD) activities were also maximum at 100 mM KCl. However, at higher KCl levels (200 mM), no significant increase in any of the morphophysiological parameters was recorded. Therefore, 100 mM KCl was identified as the optimum salt concentration for enhancing bacoside A content, plant growth, and physiological properties in terms of antioxidant enzyme activity and chlorophyll content in B. monnieri.

Heat stress presents unique challenges compared to other environmental stressors, as predicting crop responses and understanding the mechanisms for heat tolerance are complex tasks. The escalating impact of devastating climate changes heightens the frequency and intensity of heat stresses, posing a noteworthy threat to global agricultural productivity, especially in rice-dependent regions of the developing world. Humidity has been demonstrated to negatively affect rice yields worldwide. Plants have evolved intricate biochemical adaptations, involving intricate interactions among genes, proteins, and metabolites, to counter diverse external signals and ensure their survival. Modern-omics technologies, encompassing transcriptomics, metabolomics, and proteomics, have revolutionized our comprehension of the intricate biochemical and cellular shifts that occur in stressed agricultural plants. Integrating these multi-omics approaches offers a comprehensive view of cellular responses to heat stress and other challenges, surpassing the insights gained from multi-omics analyses. This integration becomes vital in developing heat-tolerant crop varieties, which is crucial in the face of increasingly unpredictable weather patterns. To expedite the development of heat-resistant rice varieties, aiming at sustainability in terms of food production and food security globally, this review consolidates the latest peer-reviewed research highlighting the application of multi-omics strategies.