Tigernut (Cyperus esculentus L.) is an herbaceous oil crop uniquely accumulating a high level of oil in the underground tubers. Water, which accounts for approximately 85% of immature tubers, is essential for tuber development and metabolism. Plasma membrane intrinsic proteins (PIPs) represent the main channel that mediates the efficient water transport across the cell membrane. This study presents the characterization of CePIP2;1, a PIP gene highly abundant in tigernut tubers. This gene with three introns was shown to encode 288 amino acids with the theoretical molecular weight of 30.34 kDa, the isoelectric point of 8.60, the grand average of hydropathicity of 0.529, and the instability index of 29.60, implying it’s stable, basic and hydrophobic characteristics. The protein was shown to possess one conservative MIP (major intrinsic protein) domain, and presence of the F-H-T-R ar/R selectivity filter and Q-S-A-F-W Froger’s positions implies a putatively efficient water transport activity. Phylogenetic analysis revealed that CePIP2;1 clusters with OsPIP2;1, OsPIP2;2, and OsPIP2;3 with the similarities of 91.72%, 90.31% and 84.98%, respectively, supporting its assignment into the PIP2 group of the PIP subfamily. Subcellular localization analysis showed that CePIP2;1 was localized to the cell membrane of Nicotiana benthamiana leaves. Although CePIP2;1 was characterized as a dominant isoform in tubers, expression analysis indicated that its transcripts were relatively more in leaves, leaf sheaths, rhizomes, and roots with the most in leaves, in contrast to a comparable level to that in shoot apexes. Among four typical stages (S₁–S₄) of tuber development examined in this study, CePIP2;1 was shown to exhibit a bell-shaped expression pattern, peaking at S₂. These results laid a solid foundation for further uncovering the mechanism of water balance in tigernut.

This study was conducted to compare the difference of heat tolerance of different Oncidium cultivars, and to establish a system for evaluating identification indexes of Oncidium heat tolerance. Seven indexes, including the leaf thickness, leaf water content and high temperature semi-lethal temperature (HLT₅₀), of 38 common O. hybridum cultivars were measured, and the yellow leaf rate and heat injury grade (HIG) of different cultivars were observed under high temperature stress. The evaluation indexes of heat tolerance of Oncidium were screened by analyzing the correlation among different indexes and combining with principal component analysis, to establish the evaluation system of heat resistance of Oncidium cultivars. The results showed that the leaf thickness, leaf water content, HLT₅₀, yellow leaf rate and HIG could well reflect the response of Oncidium to high temperature stress, which could be taken as the index for evaluating Oncidium heat tolerance. The 38 cultivars could be classified into three categories: heat-tolerant cultivars (12 cultivars), moderate heat-tolerant cultivars (3 cultivars) and non-heat-tolerant cultivars (23 cultivars) by cluster analysis based on heat-tolerant index. The results of this study could provide a reference for material selection of Oncidium in hot area, and also provide parental resource for the breeding of Oncidium with high heat tolerance.

Dendrobium are famous for the ornamental and medicinal value. In order to explore the volatile components in the flowers of Dendrobium in Sect. Holochrysa and Sect. Chrysotoxae Kraenzl., the volatile components in the flowers of five Dendrobium in Sect. Holochrysa and seven Dendrobium in Sect. Chrysotoxae Kraenzl. were extracted by solid phase micro extraction (SPME) and analyzed via gas chromatography-mass spectrometry (GC-MS). Results showed that 74 volatile components were identified from the flowers of the species, 47 of which from D. hancockii in Sect. Holochrysa were the main volatile components; Secondly, there were 37 and 35 volatile components from D. chrysotoxum and D. harveyanum in the Sect. Chrysotoxae Kraenzl., respectively. The least component species was D. farmeri in the Sect. Chrysotoxae Kraenzl. with only 18 volatile components. Most of the species of volatile substances in Dendrobium were more than 20, and most of which were alkenes, except D. kenkinsii and D. densiflorum in the Sect. Chrysotoxae Kraenzl. mainly contained aldehydes. Cluster analysis of volatile ingredients showed that all the Dendrobium flowers were clustered together except a few Dendrobium plants were not clustered in the original grouping, which indicated that the volatile substances in Dendrobium flowers could be used as a reference for Dendrobium grouping. This study would provide references for the breeding, resource exploration and utilization of Dendrobium, and exert significant value on the grouping of Dendrobium.

The effects of long-term nutrient deficiency on cassava agronomic characters, yield and starch content were studied to provide scientific basis for fertilization of continuous cropping. In this study, experimental materials in 2019 to 2021 (continuous cropping in 28th-30th years) were selected from the time axis of long-term fertilization trials. CK (with NPK), –N (without N), –P (without P), –K (without K) combined with two cassava varieties SC205 and SC124 were selected. The SPAD value, plant height, stem diameter and starch content, yield, starch yield of the fresh storage root (FSR) were measured and evaluate. Compared to CK, –N and –K significantly reduced plant height, and –N, –P and –K significantly reduced stem diameter of cassava. Meanwhile, –K significantly reduced SPAD value of leaves. Test of between-subjects effect showed that, variety or fertilization had significant effects on agronomic characters, but the interaction effect between them was not significant. The starch content of FSR, compared to CK, –N significantly improved in 2021. –K significantly reduced, the three-year average decrease was 14.2%. Compared to CK, –N, –P and –K significantly reduced the yield, starch yield of FSR, storage root number per plant (SRNPP) and weight per storage root (WPSR). The yield of FSR reduced by more than 40.0% under different nutrient deficiency, while the yield effects were insignificantly different among nutrient deficiency treatments. The starch yield of FSR under -K decreased by 53.3%, the decrease was significantly higher than that of –N and –P. The correlation analysis showed that yield, starch yield of FSR were extremely significantly positively correlated with the SRNPP, and significantly positively correlated with the WPSR. –N, –P and –K significantly inhibited cassava growth. N was the primary limiting factor for cassava fresh storage root yield in the early stage of continuous cropping, followed by K, but P effect was not obvious. With the extension of continuous cropping years, the effects of K and P effect gradually became more significant, and N, K became the main limiting factors, then there was no significant difference on the fresh storage root yield effect among N, P and K, there were equally important.

Aquilaria sinensis (Lour.) Gilg is a resin containing wood in the genus Aquilaria or Gyrinops. Among them, agarwood essential oil (AEO) is the main functional active component of agarwood, which has good neuroprotective effect and is often used to soothe the body and mind, relieve anxiety and depression, and treat insomnia. A large number of studies have shown that the chemical composition of AEO mainly includes chromones, sesquiterpenoids, aromatics, fatty acids and other compounds, among which 2-(2-phenethyl) chromone and sesquiterpenoids are the characteristic components. However, there is no clear standard for AEO classification and quality testing, and the quality of AEO is uneven, which greatly affects the development of agarwood industry. The efficacy of AEO is closely related to its chemical composition. The chemical composition and content of AEO obtained from different raw materials (species, origin, induction methods and time) and different extraction methods (hydro-distillation, supercritical fluid carbon dioxide extraction, solvent extraction) are quite different. Therefore, it will be the direction of future research to establish a sound grading and quality testing standard of AEO, and reveal the internal relationships of the chemical composition of AEO with the raw materials and extraction methods. In addition, due to the increasing demand for agarwood, the wild population of agarwood species has declined rapidly, resulting in the depletion of wild resources. However, with the popularization of artificial cultivation and induction methods, the yield of agarwood has been greatly improved, which provides a research basis for further research on AEO. This article reviews the chemical components of AEO from different sources and their application prospects in neuroprotective effects, and analyzes the problems existing in the current research of AEO.

A genus, Tolypanthus, and three species: Tolypanthus esquirolii (Lévl.) Lauener, Morus liboensis S. S. Chang and Scutellaria franchetiana Levl. from Fuyuan Shibalianshan Provincial Nature Reserve were reported as newly recorded species to Yunnan province. Voucher specimens for the reported species were preserved in the Herbarium of Kunming Institute of Botany (KUN), Chinese Academy of Sciences.

Rhizosphere is a dynamic interface where soil, plant roots and microorganisms exchange substances. Rhizospheric actinomycetes are an important component of root actinomycetes and one of the main sources of bioactive substances. In this study, five different rhizospheric soil samples of a mangrove plant, Acanthus ilicifolius, were collected from the Dongzhaigang Mangrove Nature Reserve of Hainan province. A combination of high-throughput sequencing and traditional pure culture strategies were used to explore the diversity of the rhizospheric actinomycetes of A. ilicifolius and the potential to produce bioactive substances in the samples. The V3 to V4 regions of 16S rRNA gene in the rhizospheric samples of A. ilicifolius were sequenced and analyzed by Illumina Novaseq 6000 sequencing platform. A total of 32 phyla (including 25 effectively identified phyla) were annotated, of which Proteobacteria is the dominant phyla. α-diversity analysis showed that the rhizospheric bacterial community of A. ilicifolius was very abundant. The microbial communities of actinomycetes were analyzed, and 33 validated genera, four tentative genera and 28 uncultured new genera were noted. KEGG functional prediction analysis in different levels showed that rhizospheric actinomycetes were mainly involved in the biosynthesis of secondary metabolites including various antibiotics. Meanwhile, actinomycetes were isolated by the traditional pure culture method. After isolation, purification, morphological characteristics grouping and rearrangement, the diversity of actinomycetes of mangrove A. ilicifolius was analyzed by PCR amplification, sequencing and comparison of 16S rRNA gene sequences. The antimicrobial activity was screened by the agar diffusion method. PCR-based gene screening technology was used to detect the possible antibiotic biosynthesis genes of the representative strains of PKS-I, PKS-II and NRPS. A total of 33 representative strains of rhizospheric actinomycetes were obtained from four genera, of which Streptomyces was the dominant genus, and 2 genera could not be detected by high-throughput sequencing method. The positive rates of NRPS and PKS-II genes of the representative strains were very high (more than 90%). 24.24% of rhizospheric actinomycetes had the activity against at least one or more indicator microorgnisms. In this study, high-throughput sequencing and traditional pure culture methods were used to show that rhizospheric actinomycetes of a mangrove plant A. ilicifolius from Dongzhaigang had a very rich actinomycetic diversity. The rhizospheric actinomyces of A. ilicifolius has good potential to synthesize secondary metabolites, which could provide rich microbial resources for the screening of bioactive compounds, and also provide an important basis for the development of subsequent new drugs.

AT-hook nuclear localized proteins (AHLs) are small DNA-binding protein motifs that play an important role in plant growth and development, organ construction, stress and hormone signaling response. In this study, MeAHL17 was cloned from cassava cultivar SC8. Bioinformatics methods were used to analyze MeAHL17 promoter, protein physicochemical properties, prediction of conserved functional domain and sequence comparison. The results showed that the open reading frame length of MeAHL17 gene was 939 bp, encoding a protein with 312 amino acids, its theoretical isoelectric point was 6.89, its molecular formula was C₁₄₂₀H₂₂₁₅N₄₁₅O₄₅₁S₁₁, and its molecular weight was 32.669 38 kDa. The total number of positively charged amino acid residues (Lys+Arg) was 23, the total number of negatively charged amino acid residues (Asp+Glu) was 24, the fat coefficient was 57.47, the total average hydrophilic coefficient (GRAVY) was -0.491 and the instability coefficient was 58.06. The protein contains no signal peptide, is located in the cell membrane, has no transmembrane structure, contains 5 glycosylation sites and 45 phosphorylation sites, and is an unstable hydrophilic acidic protein MeAHL17 contained AT-hook conserved core sequences and PPC domain conserved core sequences, which was consistent with the typical structural characteristics of AT-hook family. Through subcellular localization and transcriptional activity analysis experiments, MeAHL17 was proved to be a nucleus localized transcription factor with transcriptional activity. Tissue expression pattern analysis showed that MeAHL17 was mainly expressed in somatic embryo, fibrous root and callus. Different hormone treatments showed that MeAHL17 was induced by ethylene (ACC), methyl jasmonate (JA) and growth hormone (IAA), which suggested that MeAHL17 might be involved in ethylene, methyl jasmonate and growth hormone signaling pathway. Abiotic stress treatment showed that MeAHL17 was responsive to drought and salt stress. This study preliminarily identified the important role of MeAHL17 in growth and development, hormone signaling and stress, and provided theoretical basis and reference for further study of its function.

In this study, 12 coffee beans from Xishuangbanna (A, B, C), Pu’er (D, E, F), Lincang (G, H, I) and Baoshan (J, K, L) were used as the raw materials to analyze the contents of main flavor precursors and the differences of sensory products. The contents of protein, fat and reducing sugar were determined by the physicochemical analysis. The composition and content of amino acids in samples were determined by an automatic amino acid analyzer. The contents of caffeine and chlorogenic acid were determined by HPLC. 12 green coffee beans were roasted and the sensory quality was measured by cup. The color difference of coffee beans was analyzed by the Colorimetry system. The protein content ranging from 11.73 g/100 g to 14.72 g/100 g, the fat content ranging from 9.1% to 15.9%, the reducing sugar content ranging from 5.83 g/100 g to 6.26 g/100 g. 16 kinds of amino acids were detected in all the 12 samples, and methionine was not detected. The total amino acid content ranging from 10.18 g/100 g to 17.25 g/100 g. The total amino acid content of E coffee beans was the highest, and that of K coffee beans was the lowest. The caffeine content ranging from 13.73 mg/g to 15.74 mg/g, and the chlorogenic acid conten tranging from 20.97 mg/g and 32.51 mg/g. B coffee beans had the brightest color, better color scheduling and tone angle. J coffee beans were rudder than other coffees, and the hue angle was relatively poor. E coffee ripe beans and I coffee ripe beans tended to be blue. E coffee bean had better color scheduling and hue angle preference. The total score of sensory evaluation ranged from 42.79 to 46.09, the sensory score of L coffee bean was the highest, and the sensory score of A coffee bean was the lowest. Therefore, the content of main flavor components of raw coffee beans in different producing areas is different, and the sensory quality of cooked coffee beans in different producing areas is also different. The results are of great significance for the improvement of Yunnan coffee flavor quality and the screening and identification of high-quality products.

In order to investigate the effects of intercropping Centrosema pubescens or Grona styracifolia on soil physicochemical properties, microbial community structure and diversity in the litchi orchard, soil samples from 0 to 40 cm depth between litchi tree rows were collected under intercropping with either C. pubescens or G. styracifolia. Physicochemical factors such as soil organic matter, total nitrogen, total phosphorus, total potassium, nitrate nitrogen, ammonium nitrogen, available phosphorus, available potassium and pH were measured. In addition, Illumina NovaSeq sequencing platform was used for 16S amplicon sequencing to analyze the microbial communities in the soil under intercropping with C. pubescens or G. styracifolia in the litchi orchard. The results showed that the nutrient content in the 0-20 cm soil layer was generally higher than that in the 20-40 cm soil layer. In the 0-20 cm soil layer, the C. pubescens intercropping treatment increased soil organic matter by 7.06%, total nitrogen by 8.70%, and ammonium nitrogen by 103.29%, compared to the control. In the intercropping treatment with G. styracifolia, soil ammonium nitrogen increased by 69.41%, nitrate nitrogen increased by 32.48%, available phosphorus increased by 112.78%, and available potassium increased by 9.44%, compared to the control. In the 20-40 cm soil layer, the C. pubescens intercropping treatment increased soil ammonium nitrogen by 114.58%, but decreased available potassium by 48.07%, compared to the control. In the intercropping treatment with G. styracifolia, soil nitrate nitrogen decreased by 15.07%, while available phosphorus increased by 105.43% and available potassium increased by 32.60%, compared to the control. In terms of microbial diversity, the indices in the 0-20 cm soil layer were generally higher than those in the 20-40 cm soil layer. In the 0-20 cm soil layer, the ACE index and Chao1 index in the C. pubescens intercropping treatment were decreased by 7.65% and 7.68%, respectively, compared to the control. In the 20-40 cm soil layer, the ACE index and Chao1 index in the intercropping treatment with G. styracifolia were increased by 6.93% and 6.74%, respectively, compared to the control. In terms of soil microbial community structure, the dominant phyla in all soil samples were Acidobacteria, Chloroflexi, Proteobacteria, Firmicutes, and Actinobacteria, while the dominant genera were Gp2, Gp13, Bryobacter, Candidatus Solibacter and Bathyarchaeia within the Acidobacteria phylum. After intercropping, the relative abundance of Thaumarchaeota, Nitrospirae, Verrucomicrobia, Gp2, Gp13 and Bryobacter increased. Redundancy analysis indicated that pH, total potassium, total phosphorus, and available potassium were the main physicochemical factors affecting soil microbial community structure. In summary, the results of this study would provide a theoretical basis for intercropping with C. pubescens or G. styracifolia in litchi orchards.