Journal of Plant Biochemistry and Biotechnology最新文献

Sugarcane, commercially cultivated for the production of sucrose, is constantly confronted by Colletotrichum falcatum which is accountable for the catastrophic red rot disease. Membrane-bound sucrose transporters are the key controllers of short as well as long-distance transport of sucrose in plants. In the background of some recent reports suggesting the involvement of sucrose transporters and disease resistance proteins in plants’ defense responses; we have investigated the abundance of these proteins in the stalk tissues of red rot resistant (BO91), and susceptible (CoJ64) cultivars of sugarcane using nanoLCMS/MS-based approach. The results revealed the presence of eight sucrose transporters and four disease resistance proteins cumulatively in both the cultivars of sugarcane. Further, we observed that C. falcatum inoculation influenced the peptide abundance of these proteins in both the cultivars of sugarcane. Among sucrose transporters, fungal inoculation caused a significant reduction in the peptide abundance of a large number of sucrose transporter proteins in both the cultivars of sugarcane including SUT-1, 5, 6, 7, and 8. In case of disease resistance proteins, the peptide abundance of all the four disease resistance proteins (DRP-1–4) was induced by C. falcatum inoculation in red rot susceptible cultivar. Our study indicated that sucrose transporters are repressed, whereas the disease resistance proteins are induced by C. falcatum infection in both the cultivars of sugarcane. The study might be useful in unraveling the specific roles of sucrose transporters and disease resistance proteins during stress responses in plants.

An understanding of plant secondary metabolites may prove to be important for novel drug development. The objective of this investigation was to enhance the biosynthesis of alkaloid compounds aervine and methylaervine in callus-derived cell suspension cultures of Aerva javanica using biotic and abiotic elicitors. The effect of five different elicitors on the biosynthesis of aervine (AE) and methylaervine (MAE) contents was studied for 20 days to determine the concentrations suitable for their accumulation in A. javanica. The callus obtained from the shoots of A. javanica on Murashige and Skoog (MS) medium containing 2.0 mg L⁻¹ 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5 mg L⁻¹ α-naphthalene acetic acid (NAA), and their cell suspension cultures were used for the elicitation purposes. The result proved the maximum accumulation of AE and MAE contents in cell suspension culture. It was found to be 72.26 ± 0.30 mg g⁻¹ DW of MAE, showing an increase of 8.66-fold, and AE content (7.48 ± 0.39 mg g⁻¹ DW) in sodium carbonate (Na₂CO₃), whereas AE (34.10 ± 0.84 mg g⁻¹ DW) and MAE (9.69 ± 0.04 mg g⁻¹ DW) showed a 2.51-fold increase in salicylic acid. It was observed that the production of hairy root using Agrobacterium rhizogenes (MTCC 532) helps in improving aervine (42.22 ± 1.04 mg g⁻¹ DW) and methylaervine (8.30 ± 0.09 mg g⁻¹ DW) accumulation. This study will serve as an alternate protocol to improve alkaloid quantity as well as quality by elicitor stimulation. Furthermore, it may help in the sustainable production of A. javanica taxon and thereby helping in rescuing the natural sources recommended to cure several ailments.

Abiotic stresses such as high temperature, excessive cold, flood, salinity, and drought disturb the normal growth and production which aggravate morphological, physiological, biochemical, and molecular changes in plants. Common abiotic stresses that plants come in contact with are salinity, drought, flood, cold and high temperature. Molecular chaperones are known as key components of the cellular molecular machinery that are working in a broad array of biological systems in response to both normal and extreme stress conditions to sustain cellular homeostasis. Molecular chaperones help in the proper folding of misfolded or native proteins by interacting with them. We review here the role of various molecular chaperones in mitigating the abiotic stress in plants. This includes mainly heat shock proteins (HSPs). Recent advances in our understanding of the molecular mechanisms underlying HSPs responses to abiotic stresses highlight their multilevel nature including sensing, signalling, transcription, translation, and post-translational protein modifications. Based on several reports, the common, shared, and distinctive groups of HSP families related to various types of abiotic stress have been classified. This knowledge can be utilized to improve crop productivity by providing essential molecular targets for the development of multiple stress-tolerant crops through plant breeding methods and genetic engineering.

Circular RNAs (CircRNAs) represent a subset of non-coding RNAs (ncRNAs) discerned by deep sequencing, predominantly within plant cells. They serve diverse roles in regulating genes during both pre- and post-transcriptional processes. Once dismissed as “junk”, they have emerged as significant participants in controlling gene expression, particularly associated with biotic stress in several plant species. In this investigation, a total of 36 RNA-Seq datasets from two wheat varieties under control and treated conditions were obtained from two Bioprojects. We detected and characterized a total of 4960 circRNAs and elucidated their function as competitive endogenous RNAs (ceRNAs) over three distinct time durations. Subsequent downstream analysis revealed a circRNA-miRNA-mRNA network involving 115 miRNAs competing for the binding sites of 5374 mRNAs in wheat. With this user-friendly interface, we expect TaCircRNADb will serve as a valuable database in developing resilient wheat varieties and aid in the improvement of key characteristics relevant to their stress response.

Lectin (TfgL) was purified from the seeds of Trigonella foenum-graecum (Fenugreek) belonging to fabaceae family by ammonium sulphate precipitation, ion exchange and followed by size exclusion chromatography. SDS–PAGE analysis revealed that TfgL molecular weight is approximately 27 kDa. 2D-PAGE reveals the existence of two isolectins (pI values of 6.3 and 6.7) with acidic nature and charge heterogeneity. The MALDI-TOF–MS and peptide mass fingerprinting investigation of TfgL showed sequence similarity with a lectin. The hemagglutinating activity of TfgL was stable in broad range of temperature 37–90 °C and at varied pHs 3, 7.6 and 10. Far-UV circular dichroism measurements showed that TfgL is mostly composed of α-helix (84.5%), β-sheet (6.5%), β-turns (5%) and unordered structures (4%). TfgL showed conformational stability in wide range of temperatures (20‒90 °C) and pHs (3, 7.6 and 10) but lost its secondary structure in the presence of 6 M Gdn.HCl. Quenching titrations were carried out with acrylamide and iodide quenchers in order to investigate the exposure and accessibility of the protein tryptophan residues. Maximum quenching observed with acrylamide compared to iodide revealed that the Trp residues of TfgL are buried in the protein core, which is hydrophobic in nature. TfgL showed binding affinity towards porphyrin, the association constant (K_a), for MnTSPP and MnTMPyP was calculated to be 1.2 × 10⁶ M^‒1 and 3.45 × 10⁶ M^‒1, respectively.

Curcuma caesia Roxb., a critically endangered herb in the Zingiberaceae family, can be conserved through microrhizomes, which are easily transported, germinate like seeds, and are independent of seasonal variations. The current investigation attempts to induce microrhizomes of this endangered herb for conservation purpose using high concentration of sucrose. To encourage the establishment of microrhizomes, six-month-old cultures of C. caesia were transferred to Murashige and Skoog supplemented with containing 8 mg L⁻¹ benzyladenine, 8 mg L⁻¹ kinetin, 100 mg L⁻¹ citric acid, 200 mg L⁻¹ adenine sulphate, and 2 mg L⁻¹ indole-3-acetic acid (standard medium). For this, standard medium was examined with sucrose concentrations of 3%, 6%, 9%, and 12%. The standard medium with 9% sucrose showed the highest rate of microrhizome formation (now referred as microrhizome production medium, MPM). During acclimatization, the survival rate of microrhizomes exceeded 90%. The physiology behind the microrhizome formation was also evaluated using enzymatic and non-enzymatic tests on days 0, 30, and 60 after inoculation. Superoxide dismutase activity, an enzymatic defence molecule, and total soluble sugar and ascorbate content, a non-enzymatic defence molecule, both increased in the MPM microrhizomes relative to the control [shoot multiplication medium (standard medium with 3% sucrose) at day 0]. Further, protein, 2-thiobarbituric acid reactive substances, and hydrogen peroxide content also increased. The biochemical results proved that 9% sucrose in MPM induces osmotic stress which eventually led to the formation of C. caesia microrhizomes, an in vitro storage organ.

Pearl millet, considered as nutri-cereal, has better nutritional composition and quality, as compared to other cereals. Though, it is less popular due to low shelf-life of the flour. Here, we characterize the rancid behavior of three diverse genotypes of pearl millet—WGI-100 (White), Purple, and fortified Dhanshakti (complete grains and decorticated) using different quality determinants linked with shelf-life. Starch, amylose, resistant and non-resistant starch content was observed maximum in Dhanshakti, whereas amylopectin was observed maximum in cv. purple. The activities of carbohydrate degrading enzyme (α-/β-Amylases) were observed maximum on 6th days after milling (DAM) in cv. Dhanshakti. Phytic acid and micronutrients (Fe and Zn) were observed more stabilized in flour during storage. We observed gradual decrease in the storage proteins and total lipid with increase in DAM due to oxidation. Evaluation of physicochemical treatments [salt (1%), lime (1%, grains soaked for overnight), hydrothermal-infrared (HT-IR, grains steamed for 5 min followed by quick drying using IR bulbs with wavelength of 0.7–2.0 µm), kilning (live steam, quick heating), near infra-red (NIR, short wave for 5 min) and air tight aluminum pouches (50 µm thickness)] showed HT-IR to be most effective treatment in arresting the lipid hydrolysis by denaturating/aggregating the rancidity causing enzymes (lipase and lipoxygenase). We observed Dhanshakti to be better in flour quality and nutrient density, as compared to other cvs. HT-IR was observed to be most cost-effective and promising technology in enhancing the shelf-life of pearl millet flour.

Stevia plants are well-known for their ability to synthesize steviol glycosides (SGs), a natural sweetener blend. The principal SGs include stevioside (STV) and Rebaudioside-A (Reb-A), with the latter exhibiting superior sweetness and organoleptic properties. UDP glucosyltransferase-76G1 (UGT76G1) is responsible for converting STV to Reb-A, determining the intensity of sweetness. A better understanding of the structure/activity of SrUGT76G1 could provide insights into Reb-A production in stevia plants. To this end, a combination of enzymatic assays and sequencing analysis was performed using two stevia genotypes (Brazilian and Spanish) with contrasting Reb-A production capabilities (off/on). Relative expression of SrUGT76G1 gene showed remarkably higher expression (~ threefold) in Spanish samples compared to Brazilian ones. Foliar protein fractions (crude or partially purified extract) from Brazil plants were unable to convert STV into Reb-A under in vitro conditions, resulting in undetectable levels of Reb-A by HPLC. Molecular analyses revealed that the Brazilian SrUGT76G1 gene not only presents a premature stop codon, resulting in the absence of PSPG motif responsible for the binding of glycosyl groups, but also exhibits mutations affecting key amino acid residues in the acceptor-binding pocket. These alterations provide a plausible explanation for the Brazilian protein inability to catalyze the transformation of STV into Reb-A.

Graphical abstract

Zinc (Zn) biofortification of rice can address Zn malnutrition in Asia. Identification and introgression of QTLs for grain Zn content and yield (YLD) can improve the efficiency of rice Zn biofortification. In four rice populations we detected 56 QTLs for seven traits by inclusive composite interval mapping (ICIM), and 16 QTLs for two traits (YLD and Zn) by association mapping. The phenotypic variance (PV) varied from 4.5% (qPN_4.1) to 31.7% (qPH_1.1). qDF_1.1, qDF_7.2, qDF_8.1, qPH_1.1, qPH_7.1, qPL_1.2, qPL_9.1, qZn_5.1, qZn_5.2, qZn_6.1 and qZn_7.1 were identified in both dry and wet seasons; qZn_5.1, qZn_5.2, qZn_5.3, qZn_6.2, qZn_7.1 and qYLD_1.2 were detected by both ICIM and association mapping. qZn_7.1 had the highest PV (17.8%) and additive effect (2.5 ppm). Epistasis and QTL co-locations were also observed for different traits. The multi-trait genomic prediction values were 0.24 and 0.16 for YLD and Zn respectively. qZn_6.2 was co-located with a gene (OsHMA2) involved in Zn transport. These results are useful for Zn biofortificatiton of rice.

The ratio of oleic acid to linoleic acid (O/L) is crucial for determining the shelf life of peanut oil. In peanuts, the expression of the Fatty Acid Desaturase 2 (FAD2) enzyme, which converts oleic acid to linoleic acid, is regulated by two homeologous genes called AhFAD2A and AhFAD2B. It has been observed that the Indian peanut cultivar GG20 does not possess natural mutations in the AhFAD2B gene. We successfully introduced a construct called CRISPR_GG20_AhFAD2B into the de-embryonated cotyledon of the GG20 plant. The purpose of this construct was to utilize the CRISPR-Cas9 gene editing technology to modify the AhFAD2B gene. Genotyping analysis of the plants that were potentially transformed with the construct confirmed that the target-specific editing had occurred in the AhFAD2B gene. Subsequently, the edited GG20 plants were phenotypically evaluated to assess the fatty acid composition in the peanut kernels. The results showed a notable increase in the O/L ratio, which rose from 3.1 in the control to 7.3 in the edited GG20 plants. This implies that the gene editing technique successfully enhanced the oleic acid to linoleic acid ratio in the peanuts, potentially improving the shelf life of the resulting peanut oil.