Guangxi Institute of Botany

Canker disease caused by Pseudomonas syringae pv. actinidiae (Psa) is a severe bacterial infection threatening global kiwifruit production. Psa causes lignin degradation, cell wall rupture, leaf wilting, and canker formation on branches and trunks, often leading to plant death. The plant cell wall serves as a structural barrier against pathogens, with its thickness, composition, and cell density influencing disease resistance. Comparative studies between resistant germplasms Actinidia eriantha "Maohuaxiong" (A. eriantha 'MHX') and Actinidia latifolia "Kuoye" (A. latifolia 'KY') and susceptible cultivars Actinidia chinensis "Hongyang" (A. chinensis 'HY') and "Donghong" (DH) indicate that the resistant lines developed smaller lesions and slower disease progression after Psa infection, compared with susceptible cultivars. Histological and biochemical analyses revealed that "MHX" and "KY" had denser mesophyll cells and higher lignin deposition. Transcriptomic analysis and transient overexpression screening identified AcLFYL1 as a positive regulator of Psa resistance. AcLFYL1 overexpression increased cell density, lignin content, and disease resistance, while RNAi silencing produced the opposite phenotypes. Yeast one-hybrid, dual-luciferase reporter, and ChIP-qPCR assays confirmed that AcLFYL1 directly activates AcCSE, a key gene in lignin biosynthesis. Consistent with this, overexpression of AcCSE similarly increased cell density and lignin content and improved Psa resistance, whereas knockdown of AcCSE in both wild-type (WT) and AcLFYL1 overexpression lines significantly reduced lignin accumulation and compromised disease resistance. These findings demonstrate that AcLFYL1 enhances resistance by promoting lignin biosynthesis and increasing mesophyll cell density through direct regulation of AcCSE, offering valuable genetic targets for breeding Psa-resistant kiwifruit varieties.

Primulina heterotricha, a species endemic to Hainan Island, China, belongs to the Gesneriaceae family and is traditionally consumed as a wild vegetable by the Li ethnic group, the earliest inhabitants on the island. Despite its long history of use, systematic research on this species has been lacking. This study presents the first comprehensive analysis of the nutritional composition of P. heterotricha. The results reveal a high moisture content (95.4 g/100 g), and is rich in dietary fiber (2.95 g/100 g); it is characterized by low energy value (3.72 kcal/100 g) and low carbohydrate content (0.709 g/100 g). Notably, the species is characterized by exceptionally high calcium levels (289 mg/100 g), of which the predominant form is NaCl-Ca (133 mg/100 g), while other forms include H2O-Ca (67.8 mg/100 g), AIC-Ca (55.9 mg/100 g), HCl-Ca (15.3 mg/100 g), Res-Ca (8.80 mg/100 g), and HAC-Ca (8.60 mg/100 g). These findings not only confirm the high nutritional value of P. heterotricha as a calcium-rich wild vegetable resource but also underscore its potential applications in functional foods, the development of local specialty ingredients, and the preservation of the traditional dietary culture of the Li ethnic group. Moreover, this work provides a solid foundation for further research on its food industry applications and highlights the importance of documenting and safeguarding ethnobotanical knowledge in minority-inhabited regions of Hainan Island.

Clinacanthus nutans is a traditional medicinal plant widely used in Southeast Asia for treating inflammation, viral infections, and cancer. However, its molecular basis remains poorly understood. In this study, the first chromosome-scale genome of C. nutans (731.61Mbp) was assembled, with 93.76% anchored to 18 pseudochromosomes. Repetitive elements constituted 69.05% of the genome, predominantly long terminal repeat retrotransposons. Phylogenomic and synonymous substitution rate analyses revealed a Lamiales-wide whole-genome duplication event, followed by extensive chromosomal rearrangements. Gene family expansion analysis showed that segmental and dispersed duplications were the primary drivers of enzyme-coding genes (EGs) expansion involved in the flavonoid and triterpenoid pathways. Integrated transcriptomic and metabolomic analyses across five organs revealed distinct organ-specific expression and metabolite profiles. Genes exhibited pronounced differential expression between leaves and roots, with enrichment in flavonoid and triterpenoid biosynthetic pathways, highlighting functional divergence and metabolic specialization. Flavonoids were enriched in aerial tissues, whereas triterpenoids accumulated in roots. Weighted gene co-expression network analysis identified key EGs (e.g. CHS, CHI, OSC) and core transcription factors (e.g. MYB, bHLH, WRKY) potentially involved in organ-specific metabolic regulation. These findings suggest a coordinated transcriptional-metabolic regulatory framework underlying the specialized functions of different tissues. This work provides valuable genomic resources and mechanistic insights into the biosynthesis and regulation of bioactive compounds in C. nutans, thereby facilitating future research and molecular breeding of this important ethnomedicinal plant.

Abstract Pollinators are key drivers of floral evolution and diversification. While floral traits often converge in response to shared pollinators, they may diverge following pollinator shifts. Here, we examine the evolution of floral traits in Brandisia , a hemiparasitic genus endemic to East and Southeast Asia that shows notable interspecific variation. We combined field observations, a literature survey of pollination systems across Orobanchaceae, measurements of 14 floral traits, and phylogenetically informed comparative analyses. Our results show that Brandisia species are primarily bird‐pollinated, probably derived from the bee‐pollinated condition predominant in Orobanchaceae. Their flowers show typical bird‐pollination traits, including tubular corollas, exserted reproductive organs, and abundant dilute nectar. Several traits may also function to avoid antagonists through visual (e.g., red coloration inconspicuous to bees), morphological (e.g., reduced or recurved corolla lobes), or physiological (e.g., dilute nectar) barriers. Ancestral state reconstruction indicates that the common ancestor of Brandisia had moderately specialized floral traits, including solitary axillary flowers, orange‐yellow coloration, short tubular corollas, and hexose‐dominated nectar. From this ancestral condition, both more specialized and more generalized phenotypes evolved, involving 11 shifts across eight traits. Together, our findings indicate that Brandisia is predominantly bird‐pollinated in the Asian flora. Rather than resulting from major pollinator shifts, floral trait variation in Brandisia reflects a continuum of adaptation to bird pollinators, potentially shaped by fine‐scale niche partitioning. Some floral traits may also have evolved under additional selective pressures, such as avoiding bees. This study advances understanding of how bird pollinators shape floral diversification in angiosperm.

Siraitia grosvenorii fruit, a traditional medicinal and edible plant, undergoes significant alterations in quality and bioactive composition during the dehydration process. This study investigated the effects of hot-air drying at various temperatures on the physicochemical properties, antioxidant activity, and drying kinetics of S. grosvenorii fruit. The drying process was terminated when fruit moisture content reached 15%, with corresponding drying durations of 420, 225, 144, 96, and 51 h at 40 °C, 50 °C, 60 °C, 70 °C and 80 °C, respectively. Among the ten mathematical models evaluated, the Midilli–Kucuk model provided the most accurate description of the drying kinetics of S. grosvenorii fruit. Quality analysis revealed that drying reduced the sugar/acid ratio, contents of mogrosides and ascorbic acid, while increasing total phenolic and flavonoid levels. Microstructural analysis revealed that higher temperatures increased drying rates by expanding the porosity of the pulp. Based on the retention of bioactive components and antioxidant capacity, 70 °C was identified as the optimal drying temperature. Overall, these findings suggest that oven-drying optimizes drying efficiency and ensures the retention of essential bioactive constituents in S. grosvenorii.

Petrocodon gracilis T.Ding & B.Pan and P. mirus X.Z.Shi, J.X.Fu & Li H.Yang are two recently described species exhibiting nearly identical morphology. To determine whether they represent the same taxon, we compared their type localities, type materials, and morphological features and conducted phylogenetic analyses using the nuclear internal transcribed spacer (ITS) and five plastid regions ( atpI‐H , matK , rps16 , trnH‐psbA and trnL‐F ). Morphological comparisons and type information revealed that both species originated from the same population and are indistinguishable in key traits. Molecular phylogenetic analysis further showed that four samples of P. gracilis and P. mirus form a strongly supported monophyletic clade. Combined morphological and molecular evidence confirmed their conspecificity. We therefore treat P. gracilis as a synonym of P. mirus .

ABSTRACT During the study of pollination mutualisms between cecidomyiid flies and Aspidistra flowers in Guangxi, southern China, we discovered a new species of gall midge, the only known pollinator for Aspidistra saxicola. It is described as Resseliella saxicolae sp. nov., based on morphological comparison with known congeners and DNA barcoding sequencing data. The new species is distinguished by dense body setae (except the thorax), uniform flagellomeres in both sexes, longer marginal wing setae, an obvious transverse arcuate scutum (located in the posterior thorax) and curved claws longer than empodia. Its wings lack special spots or stripes, while the dense setae covering and prominent scutum ridge are unique among congeners. Mitochondrial cytochrome oxidase subunit I (COI) gene sequencing indicated that adults and larvae from A. saxicola flowers belong to the same species. Bayesian analysis showed that Resseliella saxicolae and the morphologically similar species R. kadsurae Yukawa, Sato and Xu (2011) were placed in one clade. The gall midge is diurnal and mates at nearby perch sites. In the life cycle of R. saxicolae, females oviposit in flower buds or flowers, with larvae feeding on pollen before pupating in soil. http://www.zoobank.org/urn:lsid:zoobank.org:pub:53EF132A-6929-40EF-BF0C-60E52B3D4697

BackgroundDespite significant advances in antiretroviral therapy (ART), substantial disparities in survival outcomes among people living with HIV (PLWH) persist in resource-limited settings. However, in Guangxi, a region heavily affected by the HIV/AIDS epidemic in China, research on the survival time of PLWH and its associated factors remains limited. This study aims to investigate the survival time and its influencing factors among PLWH in Guilin, Guangxi, from 1996 to 2022, filling an important gap in regional HIV epidemiological research.MethodsA retrospective cohort study method was used to study PLWH whose current address was reported as local in Guilin from 1996 to 2022. The life table method and Kaplan–Meier method were used to calculate the survival rate and draw the survival curve, and the Cox proportional hazards regression model was used to analyze the influencing factors of the survival time of PLWH.ResultsA total of 16,068 HIV/AIDS patients were included in the study, with a mortality rate of 8.67/100 person-years. The median survival time of PLWH was 14.11 years (95% CI: 13.50–15.70), and the 1-year, 3-year, 5-year, and 10-year cumulative survival rates were 72, 66, 62, and 54%, respectively. Cox proportional hazards model analysis identified factors significantly associated with increased risk of death, including male sex (HR = 1.425, 95% CI: 1.334–1.522), older age, low education level, unmarried status, farming occupation, and not receiving ART (HR = 10.578, 95% CI: 9.880–11.326). In contrast, individuals infected through heterosexual transmission and those identified through counseling and testing services had better survival outcomes. Lower CD4+T lymphocyte count at enrollment was associated with a higher risk of death.ConclusionSurvival time of PLWH is affected by many factors. In the context of the continuous improvement of policies and measures of Guilin City’s anti-HIV attack project, behavioral interventions for key populations as well as publicity in rural areas should be strengthened, and early detection and treatment should be advocated in order to improve the quality of survival of PLWH and prolong their survival time. The findings of this study can provide scientific evidence for optimizing HIV prevention and control strategies in similar settings.

Following a bryological investigation of Shiwandashan National Nature Reserve in Guangxi, China, Acromastigum herzogii is reported as a new national record, accompanied by a detailed morphological description. Furthermore, two additional species of Lepidoziaceae, Kurzia borneensis and Zoopsis liukiuensis, are documented. The taxonomically poorly understood species K. borneensis is considered here as a distinct and well-circumscribed taxon, new to mainland China. The genus Zoopsis is recorded for the first time from Guangxi.