Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; Guangxi Eco-engineering Vocational and Technical College, Liuzhou, Guangxi, China.
Environ Res. 2024 Jul 1;252(Pt 4):119069. doi: 10.1016/j.envres.2024.119069. Epub 2024 May 10.
Dwarf bamboo (Indocalamus decorus) is an O-tolerant plant species. To identify the possible mechanism and response of leaf morphological, antioxidant, and anatomical characteristics to elevated atmospheric O (EO) concentrations, we exposed three-year-old I. decorus seedlings to three O levels (low O-LO: ambient air; medium O-MO: Ambient air+70 ppb high O-HO: Ambient air+140 ppb O) over a growing season using open-top chambers. Leaf shape and stomatal characteristics, and leaf microscopic structure of I. decorus were examined. The results indicated that 1) the stomata O flux (F) of HO decreased more rapidly under EO as the exposure time increased. The foliar O injury of HO and MO occurred when AOT40 was 26.62 ppm h and 33.20 ppm h, respectively, 2) under EO, leaf number, leaf mass per area, leaf area, and stomata length/width all decreased, while leaf thickness, stomatal density, width, and area increased compared to the control, 3) MDA and total soluble protein contents all showed significantly increase under HO (36.57% and 32.77%) and MO(31.91% and 19.52%) while proline contents only increased under HO(33.27%). 4) MO and HO increased bulliform cells numbers in the leaves by 6.28% and 23.01%, respectively. HO reduced the transverse area of bulliform cells by 13.73%, while MO treatments had no effect, and 5) the number of fusoid cells interspace, the transverse area of fusoid cells interspace, and mesophyll thickness of HO significantly increased by 11.16%, 28.58%, and 13.42%, respectively. In conclusion, I. decorus exhibits strong O tolerance characteristics, which stem from adaptions in the leaf's morphological, structural, antioxidant, and anatomical features. One critical attribute was the enlargement of the bulliform cell transverse area and the transverse area of fusoid cells interspace that drove this resistance to O. Local bamboo species with high resistance to O pollution thus need to be promoted for sustained productivity and ecosystem services in areas with high O pollution.
dwarf 竹子（Indocalamus decorus）是一种对 O 耐受的植物物种。为了确定叶片形态、抗氧化剂和解剖特征对大气 O 浓度升高的可能机制和响应，我们使用开顶室将三年生的 I. decorus 幼苗暴露在三种 O 水平下（低 O-LO：环境空气；中 O-MO：环境空气+70 ppb 高 O-HO：环境空气+140 ppb O）超过一个生长季节。检查了 I. decorus 的叶形和气孔特征以及叶片微观结构。结果表明：1）随着暴露时间的增加，HO 中的气孔 O 通量（F）在 EO 下下降得更快。当 AOT40 分别为 26.62 ppm·h 和 33.20 ppm·h 时，HO 和 MO 的叶片 O 损伤发生；2）在 EO 下，叶片数、叶面积比、叶面积和气孔长度/宽度均降低，而叶片厚度、气孔密度、宽度和面积增加与对照相比，3）MDA 和总可溶性蛋白含量在 HO（36.57%和 32.77%）和 MO（31.91%和 19.52%）下均显著增加，而脯氨酸含量仅在 HO 下增加（33.27%）。4）MO 和 HO 分别使叶片中的泡状细胞数量增加了 6.28%和 23.01%。HO 使泡状细胞的横截面积减少了 13.73%，而 MO 处理则没有影响；5）HO 的梭形细胞间隙数量、梭形细胞间隙的横截面积和叶肉厚度分别显著增加了 11.16%、28.58%和 13.42%。总之，I. decorus 表现出很强的 O 耐受特性，这源于叶片形态、结构、抗氧化和解剖特征的适应性。一个关键特征是泡状细胞横截面积和梭形细胞间隙横截面积的增大，这推动了对 O 的抗性。因此，在高 O 污染地区，需要推广具有高 O 污染抗性的本地竹种，以维持生产力和生态系统服务。
