Search Results (47)

In this study, we assessed soil pollutants and surveyed the bacterial communities using 16S rRNA sequencing to better understand how to improve rehabilitation strategies for nickel-laterite mines in the Philippines. Representative soil samples and rhizospheres from Saccharum spontaneum L. in three post-mining sites rehabilitated in 2015, 2017, and 2019 were collected and analyzed. X-ray diffraction (XRD) identified iron oxyhydroxides, silicates, and clays as major soil components. Based on the pollution load index and contamination degree, the 2015A and 2015B sites were classified as “pristine” and had a “low degree of pollution”, while the remaining sites (2017A, 2017B, 2019A, and 2019B) were considered “moderately contaminated” with nickel, chromium, cobalt, lead, zinc, and copper. An analysis of the bacterial community composition revealed that the phyla Proteobacteria and Actinobacteria, along with the genus Ralstonia, were the most abundant groups across both control and rehabilitated sites. Our results showed that the soil pH and organic matter contents were strongly linked to specific bacterial community composition. These taxa have potential for inoculation in nickel-laterite soils to promote the growth of hyperaccumulator plants. Our results also showed a significant correlation between the structure of the bacterial communities and nickel, chromium, and manganese soil contents, but not with rehabilitation time. Furthermore, we identified the genera Diaphorobacter as potential bioindicators because they are sensitive to nickel and chromium. This study provides valuable baseline data on heavy metal pollution and microbial diversity in a rehabilitated Ni-laterite mine site. Full article

The increasing demand for renewable energy, coupled with the urgent challenges posed by climate change, has positioned perennial biomass crops (BPGs) as essential and sustainable alternatives for bioenergy production. This study investigated the impact of irrigation regimes on the physiological performance of three BPG species—Arundo donax L., Saccharum spontaneum, and Miscanthus—with a focus on leaf gas exchange (net assimilation rate and transpiration rate) and instantaneous water use efficiency (iWUE) at varying levels of irrigation input, adopting a split-plot experimental design under the Mediterranean climatic conditions of Sicily (Italy). The results clearly showed that A. donax, a C3 species, outperformed the C4 species S. spontaneum and Miscanthus, exhibiting significantly higher stomatal conductance and net photosynthesis, especially under irrigated conditions. S. spontaneum demonstrated the highest iWUE, particularly in rainfed treatments, reflecting its efficient use of water. Miscanthus showed the greatest sensitivity to water stress, with a more pronounced decline in photosynthesis during drought periods. This study accentuated the role of effective water management and genotype selection in optimizing biomass yield and resource efficiency, providing valuable insights for improving crop productivity in Mediterranean and other semi-arid regions. Full article

Fructose-1,6-bisphosphatase (FBP) is a crucial regulatory enzyme in sucrose synthesis and photosynthetic carbon assimilation, functioning through two distinct isoforms: cytosolic FBP (cyFBP) and chloroplastic FBP (cpFBP). However, the identification and functional characterization of FBP genes in Saccharum remains limited. In this study, we conducted a systematic identification and comparative genomics analyses of FBPs in three Saccharum species. We further examined their expression patterns across leaf developmental zones, spatiotemporal profiles, and responses to diurnal rhythms and hormonal treatments. Our analysis identified 95 FBP genes, including 44 cyFBPs and 51 cpFBPs. Comparative analyses revealed significant divergence in physicochemical properties, gene structures, and motif compositions between the two isoforms. Expression profiling indicated that both cyFBPs and cpFBPs were predominantly expressed in leaves, particularly in maturing and mature zones. During diurnal cycles, their expression peaked around the night–day transition, with cpFBPs exhibiting earlier peaks than cyFBPs. FBP genes in Saccharum spontaneum displayed greater diurnal sensitivity than those in Saccharum officinarum. Hormonal treatments further revealed significant regulatory divergence in FBP genes, both between isoforms and across species. Notably, cyFBP_2 and cpFBP_2 members consistently exhibited higher expression levels across all datasets, suggesting their pivotal roles in sugarcane physiology. These findings not only identify potential target genes for enhancing sucrose accumulation, but also highlight the breeding value of S. spontaneum and S. officinarum in sugarcane breeding. Full article

Saccharum spontaneum serves as an essential genetic resource for sugarcane improvement. Traditional breeding methods, characterized by slow selection and limited germplasm exploitation, often lead to suboptimal progeny performance. In this study, we revised the utilization strategy by initially hybridizing several S. spontaneum clones, followed by intercrossing their F1 progeny to establish a heterogeneous ‘polymeric’ population, which was then subjected to ‘nobilization’. A natural Saccharum spontaneum (S0) plant was used as the parent to create a hybrid (S1) containing two S. spontaneum bloodlines. The agronomic traits of S1 were compared, leading to the identification of three superior hybrids. These hybrids were then crossed in a complete diallel design, resulting in six crosses. Significant genetic variation was observed for the agronomic traits. Compared with S0, the plant height in S1 increased by 31.5%, and by 32.22% in S2. The stem diameter in S1 increased by 38.71%, and by 51.61% in S2. The single stem weight increased by 125% in S1 and 150% in S2. Other yield traits also showed varying degrees of improvement. A correlation analysis indicated that the plant height, stalk diameter, single stalk weight, and leaf width were significantly positively correlated with yield, and the leaf width with brix. There was no significant correlation between the millable stalks and yield. This study successfully developed a novel S. spontaneum hybrid with significantly improved agronomic traits, enhancing the genetic foundation of S. spontaneum germplasm for nobilization breeding programs. These findings provide a valuable germplasm base for developing high-performance sugarcane varieties, improving the utilization of S. spontaneum. Full article

Interspecific hybridization serves as a crucial strategy for innovating sugarcane germplasms. Currently, nearly all modern sugarcane varieties that incorporate genetic material are derived from Saccharum spontaneum. The number of chromosomes in S. spontaneum ranges from 40 to 128, contributing significantly to the diversity of its genetic resources. However, the genetic mechanisms driving chromosome number variation in S. spontaneum remain to be fully elucidated. Here, oligonucleotide fluorescence in situ hybridization (Oligo-FISH) was conducted to identify individual chromosomes and explore chromosome transmission during the intraspecific hybridization of S. spontaneum. The results indicate that from the progenies generated from S. spontaneum Yunnan2017-22 (2n = 8x = 64) and Yunnan82-1 (2n = 8x = 64) emerged two distinct karyotypes, 2n = 12x = 96 (A1) and 2n = 8x = 64 (A2, A33-1, A18). This implies that the chromosome inheritances were 2n + n and n + n in the progenies. However, self-pollinated samples of A1 (2n = 12x = 96) produced normal offspring C1 (2n = 94) and C2 (2n = 96). The 2n + n inheritance pattern did not continue. In another cross, the progenies derived from S. spontaneum Yunnan2017-41 (2n = 8x = 64) and Yunnan8 (2n = 10x = 80) carried a karyotype of 2n = 9x = 72, with n + n inheritance mode. These findings highlight the existence of two chromosome inheritance modes, 2n + n and n + n, in the context of the intraspecific hybridization of S. spontaneum. Additionally, hybridization between different ploidy S. spontaneum was also accompanied by chromosomal translocations (A1, A2, A18, A18) and loss (A2, A33-1, AA-4, and C2) that further resulted in the complexity of the S. spontaneum genome. Together, these findings highlight diverse chromosome inheritance in S. spontaneum hybridization, and provide a theoretical foundation for the further utilization of S. spontaneum germplasm in sugarcane breeding. Full article

Sugarcane (Saccharum spp.) is globally considered an important crop for sugar and biofuel production. During sugarcane production, the heavy reliance on chemical nitrogen fertilizer has resulted in low nitrogen use efficiency (NUE) and high loss. Up until now, there has been extensive research on the transcriptomic dynamics during sugarcane response to low nitrogen (LN) stress. However, the specific contribution of S. spontaneum to the NUE of modern sugarcane remains unclear. In the present study, the comparative transcriptome analysis of two contrasting sugarcane cultivars in response to nitrogen deficiency was performed via the combination of genomes of S. spontaneum and S. officinarum. Sub-genome analysis indicated that S. spontaneum supports the high NUE of modern sugarcane by providing genes related to nitrogen and carbohydrate metabolism, photosynthesis, and amino acid metabolism. Additionally, the key genes involved in nitrogen metabolism from the S. spontaneum were successfully identified through weighted gene co-expression network analyses (WGCNA), and a high-affinity nitrate transporter named ScNRT2.3 was subsequently cloned. Heterogeneous expression of the ScNRT2.3, a cell membrane-localized protein, could enhance the growth of Arabidopsis under low nitrate conditions. Furthermore, a conserved protein module known as NAR2.1/NRT2.3 was shown to regulate the response to LN stress in sugarcane roots through molecular interaction. This work helps to clarify the contribution of S. spontaneum to the NUE in modern sugarcane, and the function of the ScNRT2.3 in sugarcane. Full article

The dwindling availability of agricultural land, caused by factors such as rapid population growth, urban expansion, and soil contamination, has significantly increased the pressure on food production. To address this challenge, cultivating non-food crops on contaminated land has emerged as a promising solution. This approach not only frees up fertile soil for food production but also mitigates human exposure to contaminants. This work aimed to examine the impact of soil contamination with Cd, Pb, Ni, and Zn on the growth, productivity, metal accumulation, and the tolerance of five lignocellulosic non-food crops: switchgrass (Panicum virgatum L.), biomass sorghum (Sorghum bicolor L. Moench), giant reed (Arundo donax L.), African fodder cane (Saccharum spontaneum L. spp. aegyptiacum Willd. Hackel), and miscanthus (Miscanthus × giganteus Greef et Deu.). A two-year pot experiment was conducted in Greece, Italy, and Portugal, following the same protocols and applying various levels of metals: Cd (0, 4, 8 mg kg⁻¹), Pb and Zn (0, 450, 900 mg kg⁻¹), and Ni (0, 110, 220 mg kg⁻¹). The experimental design was completely randomized, with three replicates for each treatment. The results showed that switchgrass and sorghum generally maintained their height and productivity under Cd and Pb stress but were adversely affected by high Zn and Ni concentrations. Giant reed and African fodder cane showed reduced height and productivity at higher Ni and Zn levels. Miscanthus exhibited resilience in height but experienced productivity reductions only at the highest Zn concentration. Heavy metal uptake varied among crops, with switchgrass and sorghum showing high Cd and Pb uptake, while giant reed accumulated the most Cd and Zn. Miscanthus had the highest Ni accumulation. The tolerance indices indicated that switchgrass and sorghum were more tolerant to Cd and Zn at lower concentrations, whereas miscanthus had lower tolerance to Cd but a higher tolerance to Zn at higher concentrations. Giant reed and African fodder cane demonstrated stable tolerance across most heavy metals. Accumulation indices highlighted the effectiveness of switchgrass and sorghum in Cd and Pb uptake, while miscanthus excelled in Ni and Zn accumulation. The cluster analysis revealed similar responses to heavy metal stress between African fodder cane and giant reed, as well as between sorghum and miscanthus, with switchgrass displaying distinct behavior. Overall, the study highlights the differential tolerance and accumulation capacities of these crops, indicating the potential for phytoremediation applications and biomass production in heavy metal-contaminated soils. Full article

Saccharum is relatively new to 33° N latitude. S. spontaneum readily hybridizes with commercial sugarcane (Saccharum spp.) and lends cold tolerance and greater yield to the hybrid progeny, called energycane. Since 2007, there have been numerous new hybrid and backcross energycane genotypes developed but there is a paucity of information about them. Twenty energycane genotypes were tested in the first season of growth from cane propagules (plant cane; PC) against Ho 02-113 (a control) for two site-years in northcentral Mississippi. Grand (exponential) growth continued into October. The prevailing paradigm is that tonnage is what matters. Except for percentage cellulose, all factors tested (dry matter yield, extractable juice volume, °Brix, theoretical ethanol from fermentation, theoretical ethanol from cellulose, and total theoretical ethanol) were greater from the second site-location compared to the first. Dry matter yield (DMY) and total theoretical ethanol yield (TTEY) were moderately correlated. Over the two years of this test only Ho 14-9213 exceeded in mean DMY of Ho 02-113. Sixteen of the 19 test genotypes in this test equaled or exceeded the mean TTEY of Ho 02-113. Full article

The auxin/indoleacetic acid (Aux/IAA) family plays a central role in regulating gene expression during auxin signal transduction. Nonetheless, there is limited knowledge regarding this gene family in sugarcane. In this study, 92 members of the IAA family were identified in Saccharum spontaneum, distributed on 32 chromosomes, and classified into three clusters based on phylogeny and motif compositions. Segmental duplication and recombination events contributed largely to the expansion of this superfamily. Additionally, cis-acting elements in the promoters of SsIAAs involved in plant hormone regulation and stress responsiveness were predicted. Transcriptomics data revealed that most SsIAA expressions were significantly higher in stems and basal parts of leaves, and at nighttime, suggesting that these genes might be involved in sugar transport. QRT-PCR assays confirmed that cold and salt stress significantly induced four and five SsIAAs, respectively. GFP-subcellular localization showed that SsIAA23 and SsIAA12a were localized in the nucleus, consistent with the results of bioinformatics analysis. In conclusion, to a certain extent, the functional redundancy of family members caused by the expansion of the sugarcane IAA gene family is related to stress resistance and regeneration of sugarcane as a perennial crop. This study reveals the gene evolution and function of the SsIAA gene family in sugarcane, laying the foundation for further research on its mode of action. Full article

Plant resistance against biotic stressors is significantly influenced by pathogenesis-related 1 (PR1) proteins. This study examines the systematic identification and characterization of PR1 family genes in sugarcane (Saccharum spontaneum Np-X) and the transcript expression of selected genes in two sugarcane cultivars (ROC22 and Zhongtang3) in response to Ustilago scitaminea pathogen infection. A total of 18 SsnpPR1 genes were identified at the whole-genome level and further categorized into four groups. Notably, tandem and segmental duplication occurrences were detected in one and five SsnpPR1 gene pairs, respectively. The SsnpPR1 genes exhibited diverse physio-chemical attributes and variations in introns/exons and conserved motifs. Notably, four SsnpPR1 (SsnpPR1.02/05/09/19) proteins displayed a strong protein–protein interaction network. The transcript expression of three SsnpPR1 (SsnpPR1.04/06/09) genes was upregulated by 1.2–2.6 folds in the resistant cultivar (Zhongtang3) but downregulated in the susceptible cultivar (ROC22) across different time points as compared to the control in response to pathogen infection. Additionally, SsnpPR1.11 was specifically upregulated by 1.2–3.5 folds at 24–72 h post inoculation (hpi) in ROC22, suggesting that this gene may play an important negative regulatory role in defense responses to pathogen infection. The genetic improvement of sugarcane can be facilitated by our results, which also establish the basis for additional functional characterization of SsnpPR1 genes in response to pathogenic stress. Full article

Due to complex polyploid, sugarcane whole genome sequencing and characterization lag far behind other crops. PCR-based DNA markers are a viable low-cost option to evaluate genetic diversity and verify genotypes. In this study, the 5S ribosomal RNA-intergenic spacer (ITS) of 171 accessions of Saccharum spp. and Tripidium spp. was dissected, including 30 accessions of S. officinarum, 71 of S. spontaneum, 17 of S. robustum, 25 of S. barberi, 13 of S. sinense, 2 of S. edule, 5 sugarcane cultivars (Saccharum spp. hybrids), 6 of Tripidium spp. (formally Erianthus spp.), and 2 of unknown species. The ITS spacers were amplified from 10 ng of the leaf DNA of each accession with the universal PCR primers PI and PII. The PCR-amplified spacers (amplicons) were analyzed by both agarose gel and capillary electrophoresis (CE). While agarose gel electrophoresis revealed five banding patterns, a total of 42 polymorphic amplicons, ranging from 60 to 506 bp, were detected by CE. Three amplicons, 234-, 235-, and 236-bp in size, were amplified from all accessions of six Saccharum species, except for three S. robustum accessions (Molokai 5573, NG 57-054, and NG 77-235) that lacked the 236-bp amplicon. The 234-, 235-, 236-bp banding pattern found in S. spontaneum was less consistent than other Saccharum species, sometimes missing a few but not all the bands in this region. An amplicon of 61-bp was amplified only from the sugarcane hybrid varieties. The PI/PII patterns indicated diversity and subpopulations within Saccharum, which could potentially be used in Breeding. Moreover, all Saccharum-specific amplicons were mostly absent in Tripidium spp. accessions, which produced 405-bp and 406-bp amplicons, and any pattern of the exceptions indicated misidentification. The T. bengalense accession Kalimpong had a unique CE-banding pattern that was different from all other accessions. Although the clustering pattern of the 42 amplicons only discriminated at the genus level, these amplicons helped identify nine misclassified accessions. This study further demonstrates that these PI/PII amplicons could be particularly useful markers for breeders at sugarcane field stations to quickly confirm and discriminate among the accessions of germplasm collections. Full article

Interspecific hybridization between commercial and wild canes followed by backcrossing may transfer favorable alleles responsible for drought tolerance in sugarcane. Our study aimed to assess the distribution of BC₁ individuals on leaf anatomy and to classify them regarding heterosis values. Five BC₁ populations were established using a commercial Saccharum spp. hybrid as a donor female and the F₁ interspecific hybrids as recurrent males. Leaf anatomy included leaf thickness (LT), cuticle thickness (CT), the vertical length of bulliform cell (VBC), stomatal crypt depth (SCD), percent CT, percent VBC, and percent SCD. The anatomical traits of BC₁ showed high phenotypic variations, and all populations can be divided into three groups based on their heterosis values. Heterosis seemed to be genotype and trait dependent as the estimates varied considerably across populations and observed traits, ranging from negative on LT to positive on VBC. Group I (BC₁-1) showed positive heterosis on percent CT, percent VBC, and percent SCD. Dendrogram analysis revealed that some clones in population BC₁-1 were promising regarding stalk weight and leaf anatomy, making them desirable for further clone selections. Backcrossing with commercial canes resulted in higher BC₁ means than their mid-parents despite low heterosis on leaf anatomy. Full article

Background: It has been recognized from the early days of allergology that aerobiological investigations have an important role to play in the development of respiratory allergic diseases. An increasing number of allergic complaints occurred among the atopic population during the blooming season of Kans grass, Saccharum spontaneum (SS), an obnoxious weed growing in and around suburban West Bengal. The present study aimed to identify SS pollen as a potential aero allergen through aerobiological, clinical, statistical, and biochemical analyses. Methods: An aerobiological survey was conducted for 2 years followed by a clinical diagnosis of 134 local atopic patients suffering from a respiratory allergy by a standard questionnaire survey and the skin prick test (SPT) using SS antigens. The antigenic protein profile was analyzed by SDS-PAGE and the allergizing potential of this pollen was investigated by an in vitro enzyme-linked immunosorbent assay to recognize the presence of the sero-reactive proteins which were the suspected cause of the respiratory allergy. A Box-plot and regression analysis were performed to establish the significance of clinical data. Results: SS pollen was found to evoke about 70.14% sensitivity among the atopic population causing early spring hay fever, allergic rhinitis, and seasonal allergic conjunctivitis. A regression analysis for the pollen antigen for estimating the total IgE value of a patient’s sera from their specific IgE value was a novel approach by our study. The antigenic extract of pollen resolved into more than 15 distinct protein bands ranging from 14.4 to 116 kDa, some of which were found to be glycosylated. The results showed that SS pollen has a significant presence in the atmosphere, which may trigger an allergic response in immunocompromised patients. Conclusions: This is, to our knowledge, the first attempt to identify allergens from Kans pollen causing seasonal pollinosis among the Indian atopic population using an immuno-clinical approach. Full article

The aim of the present work was to assess the leaf area duration (LAD) and the radiation use efficiency (RUE) of six warm-season perennial biomass grasses (PBGs) in a two-year field trial in the semiarid Mediterranean climate under different soil water availability. Two ecotypes of giant reed (Arundo donax L., ARCT and ARMO), one ecotype of African fodder cane (Saccharum spontaneum L. subsp. aegyptiacum (Willd.) Hack., SAC) and three hybrids of Miscanthus (the commercial M. × giganteus J.M. Greef, Deuter ex Hodk., Renvoize, M × G, and two new seed-based hybrids, GNT9 and GNT10) were compared under three levels of soil water availability: rainfed, 50% and 100% of maximum crop evapotranspiration (ETm) restoration. The determination of RUE of perennial plants is controversial and has led to contrasting results in past studies. In the present work, LAD and RUE differed among crops and irrigation regimes, being positively affected by supplemental water inputs. SAC, ARCT and ARMO showed both high LAD and RUE, which determined the high biomass yield than both the commercial M × G and the improved Miscanthus hybrids GNT9 and GNT10. RUE was particularly high and less affected by soil water availability during the mid-season, while the effect of irrigation and the differences among the genotypes were larger during the late season. Adequate biomass yield can be achieved by sub-optimal soil water availability, thus reducing the water footprint and increasing the sustainability of these biomass perennial grasses selected for the Mediterranean climate. Full article

Energy cane is a genotype derived from species of sugarcane (Saccharum officinarum and Saccharum spontaneum) with a lower sucrose content and higher fiber content for bioenergy purposes. It is a rustic plant that demands less fertile soils that do not compete with food crops. In this work, an analysis of energy cane bagasse pyrolysis products was performed, assessing the effect of reaction temperature and kinetic and thermodynamic parameters. Anhydrosugars, such as D-allose, were the primary compounds derived from the decomposition of energy cane at 500 °C. Methyl vinyl ketone and acetic acid were favored at 550 and 600 °C. At 650 °C, methyl glyoxal, acetaldehyde and hydrocarbons were favored. Among the hydrocarbons observed, butane, toluene and olefins such as 1-decene, 1-undecene, 1-tridecene and 1-tetradecene were the most produced. The Friedman isoconversional method was able to determine the average activation energies in the ranges 113.7−149.4, 119.9−168.0, 149.3−196.4 and 170.1−2913.9 kJ mol⁻¹ for the decomposition of, respectively, pseudo-extractives, pseudo-hemicellulose, pseudo-cellulose and pseudo-lignin. The thermodynamic parameters of activation were determined within the ranges of 131.0 to 507.6 kJ mol⁻¹ for ΔH, 153.7 to 215.2 kJ mol⁻¹ for ΔG and −35.5 to 508.8 J mol⁻¹ K⁻¹ for ΔS. This study is very encouraging for the cultivation and use of high-fiber-content energy cane bagasse, after sucrose extraction, to produce biofuels as an alternative to the current method of conversion into electricity by low-efficiency burning. Full article