铜(Cu)是植物生长发育所必需的矿质养分,参与多种形态,生理,和生化过程;然而,高浓度的Cu会对这些过程产生负面影响。在Bruguieragynorhiza中尚未研究气孔在响应各种生物和非生物刺激中的作用,特别是它们在分子上的协调相互作用,生理,和生化水平。此外,许多植物采用策略,例如在其叶片表皮上存在厚的蜡质角质层和关闭气孔以减少水分流失。因此,本研究调查了不同Cu处理(0、200和400mgL-2,在两年的胁迫期内,分别为Cu0,Cu200和Cu400)。结果表明,Cu胁迫影响Cu的积累和迁移,增加了过氧化物酶和抗坏血酸过氧化物酶的活性,可溶性糖的浓度,脯氨酸,和H2O2,并降低过氧化氢酶活性和丙二醛含量。此外,铜胁迫降低了植物对磷和氮的吸收,抑制了植物的光合作用。从而导致植物生长减少。扫描电子显微镜结合气相色谱-质谱分析显示,在Cu胁迫下,B.gynorhiza叶片具有较高的蜡晶和组成,这迫使叶子的气孔被关闭。此外,烷烃的含量,酒精,主要酒精水平(C26:0,C28:0,C30:0和C32:0),正构烷烃(C29和C30),和其他蜡负荷明显更高,而Cu200和Cu400中的脂肪酸(C12、C16和C18)低于Cu0。此外,转录组分析显示1240(771个上调和469个下调),1000(723个上调和277个下调),分别在Cu0vsCu200、Cu0vsCu400和Cu200vsCu400中和1476个(808个上调和668个下调)差异表达基因。RNA-seq分析表明,铜主要影响8个途径,包括光合作用,角质,suberin,和蜡生物合成。该研究为了解红树林对重金属胁迫的响应和开发新的管理措施提供了参考。
Copper (Cu) is a necessary mineral nutrient for plant growth and development and is involved in several morphological, physiological, and biochemical processes; however, high concentrations of Cu can negatively impact these processes. The role of stomata in responding to various biotic and abiotic stimuli has not been studied in Bruguiera gymnorhiza, particularly in terms of their coordinated interactions at the molecular, physiological, and biochemical levels. Moreover, numerous plants employ strategies such as the presence of thick waxy cuticles on their leaf epidermis and the closing of stomata to reduce water loss. Thus, this study investigates the accumulation of Cu in B. gymnorhiza and its effect on leaf morphology and the molecular response under different Cu treatments (0, 200, and 400 mg L⁻¹, Cu0, Cu200, and Cu400, respectively) during a two years stress period. The results show that Cu stress affected accumulation and transport, increased the activities of peroxidase and ascorbate peroxidase, concentrations of soluble sugar, proline, and H2O2, and decreased the activity of catalase and content of malondialdehyde. Also, Cu-induced stress decreased the uptake of phosphorus and nitrogen and inhibited plant photosynthesis, which consequently led to reduced plant growth. Scanning electron microscopy combined with gas chromatography-mass spectrometry showed that B. gymnorhiza leaves had higher wax crystals and compositions under increased Cu stress, which forced the leaf\'s stomata to be closed. Also, the contents of alkanes, alcohols, primary alcohol levels (C26:0, C28:0, C30:0, and C32:0), n-Alkanes (C29 and C30), and other wax loads were significantly higher, while fatty acid (C12, C16, and C18) was lower in Cu200 and Cu400 compared to Cu0. Furthermore, the transcriptomic analyses revealed 1240 (771 up- and 469 downregulated), 1000 (723 up- and 277 down-regulated), and 1476 (808 up- and 668 downregulated) differentially expressed genes in Cu0 vs Cu200, Cu0 vs Cu400, and Cu200 vs Cu400, respectively. RNA-seq analyses showed that Cu mainly affected eight pathways, including photosynthesis, cutin, suberin, and wax biosynthesis. This study provides a reference for understanding mangrove response to heavy metal stress and developing novel management practices.