Casuarina equisetifolia stands out as a highly valuable tree species crucial for industries and ecological restoration projects in tropical and subtropical regions, owing to its exceptional salt resistance. However, its growth is hampered in cold and drought-prone areas. Understanding the genetic basis for abiotic stress tolerance is imperative for enhancing stress-resistant breeding efforts of C. equisetifolia. However, the CBF genes are renowned for their pivotal roles in cold response and broad resilience to other adverse environments, such as drought, and high salinity. In this study, five CeCBFs were identified from the genome of C. equisetifolia. CeCBF1 and CeCBF3 belong to Clade I group, which diverged early from DREBIII members, while CeCBF2, CeCBF4, and CeCBF5 are classified into Clade II, a group innovated from Clade I. These genes lack introns in their sequences. The proteins encoded by CeCBFs feature classic AP2 domains and CBF signature sequences, localize in the nucleus and exhibit transactivation activity. Additionally, stress-related, abscisic acid, and jasmonic acid responsive elements are present on the CeCBFs promoters. Expression analysis revealed that CeCBFs were prodominantly induced by cold, drought, and salinity treatments, except for CeCBF1, which showed repression specifically under low temperature. Moreover, CeCBF1, CeCBF4, and CeCBF5 were inhibited by abscisic acid, while CeCBF1 showed reduced transcript levels in response to methyl jasmonate treatment. Furthermore, overexpression of CeCBF4 enhanced tolerance to low temperature, depriving of water, and salt by up-regulating stress-responsive genes expression and promoting proline accumulation, albeit with a trade-off in growth and productivity. Hence, CeCBFs emerge as potential regulators contributing significantly to stress tolerance mechanisms in C. equisetifolia.

NAC (NAM, ATAF and CUC)-like transcription factors, a class of plant-specific transcription factors, play a pivotal role in plant growth, development, metabolism, and stress response. Notably, a specific subclass of NAC family, known as SNAC (stress-responsive NAC), is particularly involved in the plant’s response to abiotic stress. As a very useful tree, Casuarina equisetifolia L. also has excellent stress resistance properties. To explore gene resources of C. equisetifolia which are associated with stress resistance and the molecular mechanisms that it employed is very helpful to its molecular-assisted breeding. In this study, 10 CeSNAC transcription factors were identified by constructing the phylogenetic tree of 94 CeNACs from the genome of C. equisetifolia L. together with 79 SNAC in different plant species. Phylogenetic tree analysis revealed that these 10 CeSNAC genes are classified into the ATAF (Arabidopsis transcription activation factor), NAP (NAC-like, activated by AP3/P1), and AtNAC3 subfamilies of the NAC family, all featuring the typical NAM (no apical meristem) domain, with the exception of CeSNAC7. In addition, all NAC transcription factors, except CeSNAC9, were localized in the nucleus. Examination of the CeSNAC promoter unveiled the presence of stress response elements such as a STRE (stress responsive element), an MBS (MYB binding site), an ABRE (abscisic acid responsive element) and a LTR (low temperature responsive element). Under various stress treatments, the majority of CeSNAC expressions exhibited induction in response to low temperature, drought, and high salt treatments, as well as ABA (abscisic acid) treatment. However, CeSNAC6, CeSNAC7, and CeSNAC9 were found to be inhibited specifically by drought treatment. Additionally, only CeSNAC3 and CeNAC9 expression was hindered while the rest of the CeSNAC expression were induced by MeJA (methyl jasmonate) treatment. These findings shed light on the relationship between different CeSNAC genes and their responses to abiotic stress conditions, providing valuable insights for further research into CeSNAC functions and aiding the development of stress-resistant varieties in C. equisetifolia.

To understand the spatial variability and influencing factors of soil properties developed from parent materials of red bed, taking Zhejiang Province as an example, the distribution, formation features and genetic characteristics of soils developed from parent materials of red bed in the subtropical region were examined, and the effects of paleoenvironment of red bed formation, modern topography and land-use mode on the physical and chemical properties of the soils were analyzed, and the classification of the soils was discussed. The results showed that the distribution of soils developed from parent materials of red bed was determined by the geological structure. The formation of the soils on red bed was a result of balance between physical weathering and surface erosion, while chemical weathering and decalcification led to soil acidification. The soils developed from parent materials of red bed tended to be juvenile, which was the common result of the special weathering characteristics of the parent material and the short soil forming time. The paleoenvironment of red bed formation had a profound impact on the material composition of the soils, and the modern topography affected the stage of soil development, and the land-use mode could change the vertical development of the soils. The color of soils developed from parent materials of red bed was not generally believed to always retain the color of the parent materials. In some cases, the former was different from the latter. Due to the complexity of red bed genesis and the diversity of material composition, the soils developed from parent materials of red bed were far more complex and changeable than generally believed. According to the “Chinese soil classification system”, the soils developed from parent materials of red bed in Zhejiang Province were only classified as purple soil group, and divided into calcareous purple soil and acid purple soil subgroups, which could not well reflect the changeable characteristics of soils developed from parent materials of red bed. According to the diagnostic horizons and diagnostic characteristics of “Chinese soil taxonomy”, the soils developed from parent materials of red bed in Zhejiang Province could be divided into two soil orders (Cambosols and Primosols), two suborders (Udic Cambosols and Orthic Primosols), seven soil groups and fourteen subgroups.

Background: Little is known about the clinical characteristics of idiopathic condylar resorption (ICR). The aim of this study was to examine the signs and symptoms of temporomandibular dysfunction (TMD) and evaluate the morphological characteristics of the condyles in patients with ICR. Methods: Sixty patients with ICR (41 in the bilateral ICR group and 19 in the unilateral ICR group) and forty-one healthy controls were examined. Signs and symptoms of TMD were described, and three-dimensional models of the condyles were measured and analyzed. Results: In total, 81.7% of ICR patients had self-reported symptoms and 78.3% of ICR patients had objective-found signs. The anteroposterior diameter, transverse diameter, height, maximal sectional area, volume of the condyles, axial angle, and the distance from the posterior point of the condyle to the Saggittal standard line were significantly smaller in the ICR condyles compared with the controls (p < 0.05). The condylar neck angle was significantly larger in the ICR condyles compared with the controls (p < 0.05). Conclusions: Most patients with ICR had signs and symptoms of TMD. The prevalence of clicking and opening–closing deviation was significantly different between the bilateral and the unilateral ICR groups. In patients with ICR, the size of the condyles decreased significantly; the condyles also rotated inward, moved forward, and inclined posteriorly.

[目的]在闽楠全基因组范围内鉴定WRKY家族成员,分析基因和蛋白序列结构特点及在闽楠幼苗缺磷胁迫下的表达特征,筛选响应缺磷逆境的WRKY基因,为进一步研究它们在楠木磷饥饿响应分子途径中的功能以及耐低磷胁迫分子辅助育种提供参考.[方法]利用WRKY蛋白序列的隐马尔科夫模型(pfam03106),经hmmsearch在闽楠蛋白数据库中检索,筛选WRKY基因.对获得的PbWRKYs利用Protaram、GSDS2.0、MEGA、Batch CD-Search、TBtools和ClustalX等软件进行基因结构、定位分析,蛋白理化性质、序列特征分析以及进化树构建.提取3年生闽楠植株的根、韧皮部和形成层、木质部和叶的RNA,进行转录组测序,分析PbWRKYs在不同组织中的表达特点.对半年生闽楠植株进行缺磷水培处理,60天后,分别取缺磷处理和对照的叶和根进行磷含量测定和转录组测序,分析磷缺乏条件下PbWRKYs表达特征,并对差异表达基因进行qPCR验证.[结果]鉴定到68个WRKY基因,命名为PbWRKY1-68,在各染色体上均有分布,第3号染色体上数量最多,内含子数目在1～28个之间,蛋白分子质量在19.09～115.56 kDa之间.所有PbWRKY均含有WRKY结构域及其特有的锌指结构.根据WRKY结构域数量及其所含锌指结构类型,分为3个亚类:亚类Ⅰ含2个WRKY结构域,锌指结构类型为C2H2型,共14个成员;亚类Ⅱ含1个WRKY结构域和1个C2H2型锌指结构,共47个成员,进化分析表明该亚类又分为5个经典子组Ⅱa、Ⅱb、Ⅱc、Ⅱd、Ⅱe,但其中PbWRKY37与上述子组进化上距离较远,独立成组;亚类Ⅲ含1个WRKY结构域和1个C2HC型锌指结构,共7个成员.PbWRKYs蛋白所含WRKY结构域氨基酸序列特征大部分为"WRKYGQK"型,但PbWRKY62的WRKY结构域变异为"WRKYGKK".与其他植物相比,PbWRKYs蛋白中WRKY结构域的变异率较低.PbWRKYs的组织特异性表达模式可分为5类:韧皮部和形成层中相对表达量较低;木质部中表达量高而叶片中表达量较低;韧皮部和形成层表达量较高同时叶片中表达量较低;根中表达量相对较高;叶片中表达量高而根中表达量低.闽楠幼苗缺磷处理60天后,叶和根中表达差异达到2倍以上的PbWRKY基因共21个.它们在叶片中被强烈诱导,可能参与低磷条件下叶片中磷元素的运输及再分配过程;其中,PbWRKY52、PbWRKY55、PbWRKY56、PbWRKY65和PbWRKY665个基因的表达还在根中被抑制,表明它们除了参与低磷条件下叶片中磷元素再分配,还可能参与了根部磷的吸收和转运.[结论]闽楠中WRKY基因家族成员共有68个,其蛋白序列中WRKY结构域较保守.缺磷处理60天时,有21个PbWRKY基因参与磷胁迫响应,大部分基因可能主要在叶片中参与低磷条件下磷的运输和分配.PbWRKY52、PbWRKY55、PbWRKY56、PbWRKY65和PbWRKY66除了在叶片中发挥功能外,还可能参与低磷条件下根部对磷的吸收和转运.

[目的]对巨桉Eucalyptus grandis中特有的低温响应基因EgrCIN1(Eucgr.B02882)序列及其表达特征进行分析,并探索其在植物低温响应中发挥的功能,以丰富桉树抗寒基因资源.[方法]利用生物信息学手段分析EgrCIN1基因、蛋白序列的特征和启动子上的顺式作用元件信息;采用实时荧光定量PCR(RT-qPCR)技术分析EgrCIN1在巨桉不同组织及4℃不同时间、干旱、300 mmol·L?1氯化钠(NaCl)、100μmol·L?1脱落酸(ABA)和100μmol·L?1茉莉酸甲酯(MeJA)处理下植株叶片中的表达特征;通过EgrCIN1::GFP载体瞬时转化烟草Nicotiana tabacum进行亚细胞定位;并构建CaMV35S启动子驱动的过表达载体异源转化拟南芥Arabidopsis thaliana,获得3个转基因纯合株系后,对其进行?6℃低温、0.5μmol·L?1ABA等逆境处理,分析EgrCIN1在低温胁迫响应中发挥的功能.[结果]EgrCIN1是巨桉中特有的基因,不含内含子,没有跨膜结构,启动子含有多个与逆境响应相关的顺式作用元件.该基因在茎和叶片中都有表达,而在根中不表达;在叶片中其表达受低温处理强烈诱导;同时,干旱、高盐和ABA等非生物逆境因子也能诱导叶片中EgrCIN1的表达,其编码蛋白被定位在叶绿体中.拟南芥中EgrCIN1过表达转基因株系对低温耐受性提高,对外源ABA敏感程度增强.[结论]EgrCIN1是在叶绿体表达,并可能通过ABA依赖途径参与植物低温胁迫响应,提高植物对低温的抗性.

Different aggregates vary in their ability to retain or adsorb metals in soil. Five soil profiles were sampled from different soil horizons and grouped, and the concentrations of Al, Mg, Ca, Fe, Mn, Cd, Cu and Pb were determined in six sizes of aggregates (> 2, 2-1, 1-0.6, 0.6-0.25, 0.25-0.053, < 0.053 mm). Significantly high (p < 0.05) structural stability indexes (SSI) and aggregate stability indexes (ASI) were recorded in the topsoil horizon, which may be attributed to the high soil organic matter (SOM) content in aggregates from topsoil. In addition, ASI and SSI were positively correlated (r = 0.569, p < 0.05) with each other, which indicated that the stability of soil aggregates could contribute to the structural stability of bulk soil. Moreover, accumulation factors (AF), principal component analysis (PCA) and Pearson's correlation coefficients were used for metal element assessment. The results indicated that SOM was not a key factor affecting the accumulation of Ca, Mg, Al, Fe, Mn, Pb, Cd and Cu in soil aggregates. In general, AF values for metal elements in microaggregates (< 0.25 mm) were high, which showed that metals preferred to accumulate in fine soil aggregates. The PCA and Pearson's correlation coefficients indicated that soil parent materials primarily controlled the distribution of Al, Ca, Fe, Mg and Mn, while materials derived from technogenic sources have important impacts on the distribution of Cd, Cu and Pb in soil aggregates along the soil profile.

Agricultural soils derived from black shale are typically enriched in potentially toxic metals. This is a serious problem, both in terms of the ecological environment and human health. To assess the levels of potentially toxic metals, 90 paired soil-crops samples were collected from the Anji Country, western Zhejiang province, a typical exposed black shale area in China. Concentrations and bioavailability of potentially toxic metals in the soil-crops system were measured, and the associated potential risks were further evaluated. Results showed the enrichment of potentially toxic metals (i.e. Cd, Pb, Cu, Zn and Ni) in the soil and crop samples, especially a significant accumulation of Cd. Sequential extraction data indicated that Cd in soils derived from black shale was the second most dominant element in the exchangeable fraction (mean at 33.42%) and possessed high bioavailability, whereas Pb was mostly retained in the residual fraction (mean at 76.34%) and exhibited low mobility. The total concentration as well as mobility and bioavailability of Cd were the highest in the sampled soils. This resulted in a high potential ecological risk in areas with agricultural soils derived from black shale, which could eventually jeopardize the health of local residents through various exposure pathways. Overall, our findings provide a scientific basis for developing suitable management strategies to mitigate the exposure to potentially toxic metals in high risk areas.

通过田间小区试验,探讨了化肥、有机肥、石灰石粉、结构改良剂配合施用对新垦红壤性状综合改良的效果以及对大豆产量的影响.试验结果表明:与对照相比,对土壤质量综合提升和大豆生长效果最佳的处理为石灰石粉+化肥-有机肥配合施用+结构改良剂,其次为石灰石粉+化肥-有机肥配合施用;化肥-有机肥配合施用的效果好于单施化肥或单施有机肥的效果;石灰石粉+单施有机肥处理的改土效果好于石灰石粉+化肥处理的效果,但对作物生长的效果略差于石灰石粉+化肥处理的效果.

低丘新垦耕地基础肥力低下,如何提升土壤有机质是其培肥的核心.为了解低丘新垦耕地土壤有机质的积累特点,通过系列模拟试验,探讨了土壤性状、 有机物料类别、 施石灰和水分管理等对施入低丘新垦耕地土壤中有机物料分解特点及其腐殖化系数的影响.结果表明,低丘新垦耕地中有机物料的腐殖化系数随土壤初始有机碳含量、pH值的增加而下降,黏质土壤的腐殖化系数高于壤质土壤.新垦耕地土壤中有机物料的腐殖化系数高于周边多年培肥的熟土.有机物料的腐殖化系数与土壤初始微生物生物量碳呈负相关.在新垦耕地中施用石灰石粉可促进土壤中有机物料的分解,降低有机物料的腐殖化系数.缺水和过多水条件下有机物料在土壤中的腐殖化系数均高于正常水分条件下.有机物料来源可明显影响其在低丘新垦耕地土壤中的腐殖化系数:堆肥大于秸秆、 绿肥;作物地下部分高于地上部分.施用生物质炭虽然能明显增加土壤有机碳的积累,但单施生物质炭不利于土壤腐殖质的形成,在新垦耕地上生物质炭应与其他有机物料配合施用.