Li Shubin, Yang Li, Huang Xiaoyan, Zou Zhiguang, Zhang Maxiao, Guo Wenjuan, Addo-Danso Shalom Daniel, Zhou Lili
Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Chinese Fir Engineering Technology Research Center of the State Forestry and Grassland Administration, Fuzhou 350002, China.
Plants (Basel). 2023 May 29;12(11):2140. doi: 10.3390/plants12112140.
Mineral accumulation in plants under drought stress is essential for drought tolerance. The distribution, survival, and growth of Chinese fir ( (Lamb.) Hook.), an evergreen conifer, can be affected by climate change, particularly seasonal precipitation and drought. Hence, we designed a drought pot experiment, using 1-year-old Chinese fir plantlets, to evaluate drought effects under simulated mild drought, moderate drought, and severe drought, which corresponds to 60%, 50%, and 40% of soil field maximum moisture capacity, respectively. A treatment of 80% of soil field maximum moisture capacity was used as control. Effects of drought stress on mineral uptake, accumulation, and distribution in Chinese fir organs were determined under different drought stress regimes for 0-45 days. Severe drought stress significantly increased phosphorous (P) and potassium (K) uptake at 15, 30 and 45 days, respectively, within fine (diameter < 2 mm), moderate (diameter 2-5 mm), and large (diameter 5-10 mm) roots. Drought stress decreased magnesium (Mg) and manganese (Mn) uptake by fine roots and increased iron (Fe) uptake in fine and moderate roots but decreased Fe uptake in large roots. Severe drought stress increased P, K, calcium (Ca), Fe, sodium (Na), and aluminum (Al) accumulation in leaves after 45 days and increased Mg and Mn accumulation after 15 days. In stems, severe drought stress increased P, K, Ca, Fe, and Al in the phloem, and P, K, Mg, Na, and Al in the xylem. In branches, P, K, Ca, Fe, and Al concentrations increased in the phloem, and P, Mg, and Mn concentrations increased in the xylem under severe drought stress. Taken together, plants develop strategies to alleviate the adverse effects of drought stress, such as promoting the accumulation of P and K in most organs, regulating minerals concentration in the phloem and xylem, to prevent the occurrence of xylem embolism. The important roles of minerals in response to drought stress should be further evaluated.
干旱胁迫下植物体内的矿物质积累对于耐旱性至关重要。常绿针叶树杉木（(Lamb.) Hook.）的分布、存活和生长会受到气候变化的影响，特别是季节性降水和干旱。因此，我们设计了一项干旱盆栽试验，使用1年生杉木幼苗，以评估在模拟轻度干旱、中度干旱和重度干旱条件下的干旱影响，这三种干旱程度分别对应土壤田间最大持水量的60%、50%和40%。以土壤田间最大持水量的80%作为对照处理。在不同干旱胁迫条件下持续0至45天，测定干旱胁迫对杉木各器官矿物质吸收、积累和分布的影响。重度干旱胁迫分别在第15天、30天和45天显著增加了细根（直径<2毫米）、中根（直径2 - 5毫米）和粗根（直径5 - 10毫米）对磷（P）和钾（K）的吸收。干旱胁迫降低了细根对镁（Mg）和锰（Mn）的吸收，增加了细根和中根对铁（Fe）的吸收，但降低了粗根对铁的吸收。重度干旱胁迫在45天后增加了叶片中P、K、钙（Ca）、铁（Fe）、钠（Na）和铝（Al）的积累，在15天后增加了Mg和Mn的积累。在茎中，重度干旱胁迫增加了韧皮部中P、K、Ca、Fe和Al的含量，以及木质部中P、K、Mg、Na和Al的含量。在枝条中，重度干旱胁迫下韧皮部中P、K、Ca、Fe和Al的浓度增加，木质部中P、Mg和Mn的浓度增加。总体而言，植物会形成一些策略来减轻干旱胁迫的不利影响，例如促进大多数器官中P和K的积累，调节韧皮部和木质部中的矿物质浓度，以防止木质部栓塞的发生。矿物质在应对干旱胁迫中的重要作用应进一步评估。
