摘要
【目的】探明嫁接对苦瓜幼苗耐镉(Cd)能力的调控作用及机理。【方法】以丝瓜‘银砧’为砧木、苦瓜‘超秀’为接穗进行嫁接,苦瓜‘超秀’自根苗为对照,设置0 mg/kg(对照)和5 mg/kg Cd处理,研究苦瓜幼苗生长指标参数、丙二醛(MDA)含量、相对电导率(REC)、抗氧化酶[超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)]活性,以及Cd积累特征的变化。【结果】Cd处理下,苦瓜幼苗各项生长指标均显著下降,但苦瓜嫁接苗的生长指标均显著高于苦瓜自根苗,其中苦瓜嫁接苗根系和地上部的干重分别为苦瓜自根苗的1.73和1.13倍。Cd处理下,苦瓜的MDA含量和REC显著升高,抗氧化酶活性均有所降低,其中苦瓜嫁接苗根和叶的MDA含量和REC的升幅低于苦瓜自根苗,抗氧化酶活性升幅均显著高于苦瓜自根苗。苦瓜幼苗根系和地上部的Cd含量在Cd处理下显著增加,Cd含量、生物富集系数(BCF)、转运系数(TF)均表现出苦瓜嫁接苗低于苦瓜自根苗的趋势,其中根系和地上部的Cd含量分别为苦瓜自根苗的69.17%和51.79%,TF为苦瓜自根苗的74.87%。Cd在苦瓜自根苗根和叶中主要集中在细胞壁和可溶性组分中,占比分别为45.06%~49.87%、45.84%~51.17%,在苦瓜嫁接苗中则主要集中在细胞壁(54.68%~58.29%)上,可溶性组分次之(38.35%~40.32%)。【结论】嫁接能够通过增强抗氧化酶活性,减轻细胞受到的膜脂过氧化伤害;同时能有效减少植株对Cd的吸收和转运,增强细胞壁对Cd的固持作用以降低苦瓜幼苗中Cd的积累,从而有效提高苦瓜幼苗的Cd耐性。
【Objective】This study clarified the regulatory effects and mechanisms of grafting on the cadmium(Cd)tolerance in bitter gourd seedlings.【Method】Using the luffa'Yinzhen'as rootstock and bitter gourd'Chaoxiu'as scion for grafting(GB),and self-rooted bitter gourd'Chaoxiu'seedling(SB)as the control.Both control and 5 mg/kg Cd treatment were set up to study on the changes of the growth parameters,malondialdehyde(MDA)content,relative electrical conductivity(REC),antioxidant enzymes activities[superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),ascorbate peroxidase(APX)],Cd accumulation characteristics in bitter gourd seedlings.【Result】Under Cd treatment,the growth indexes of bitter gourd seedlings were significantly reduced,but the growth indexes of GB were significantly higher than those of SB,in which the dry weight of roots and shoots of GB were 1.73 and 1.13 times that of SB,respectively.The MDA content and REC of bitter gourd were significantly increased,and the antioxidant enzyme activities were reduced under Cd treatment.The increase in MDA content and REC in the roots and leaves of GB was lower than that of SB,whereas the antioxidant enzymes activities were significantly higher.The Cd concentrations in the roots and shoots of bitter gourd increased significantly under Cd treatment.The Cd concentrations,bio-concentration factor(BCF)and translocation factor(TF)showed a trend that the GB were lower than the SB.The Cd concentrations in the roots and shoots of GB were 69.17%and 51.79%of those in SB,respectively,and the TF of GB was 74.87%of that in SB,most Cd accumulated in the cell wall and the soluble fraction in the roots and leaves,with the proportion of 45.06%-49.87%and 45.84%-51.17%,respectively.In GB,Cd was mainly accumulated in the cell wall(54.68%-58.29%),followed by the soluble fraction(38.35%to 40.32%).【Conclusion】Grafting can reduce the damage of membrane lipid peroxidation by enhancing the activity of antioxidant enzymes.It also effectively reduces the absorption and transportation of Cd within the plant,thereby enhancing the cell wall's ability to retain Cd and thus lowering the accumulation of Cd in bitter melon seedlings.Therefore,grafting significantly improves the Cd tolerance in bitter melon seedlings.
作者
月培茜
王慧慧
何旭颖
马艺荣
杨立勋
贾永霞
YUE Peixi;WANG Huihui;HE Xuying;MA Yirong;YANG Lixun;JIA Yongxia(College of Resources,Sichuan Agricultural University,Chengdu 611130,China;Chengdu Newsun Crop Science Co.,Ltd.,Chengdu 611630,China)
出处
《四川农业大学学报》
北大核心
2025年第6期1565-1572,共8页
Journal of Sichuan Agricultural University
基金
四川省重点研发项目(2024YFNH0001)。
关键词
镉胁迫
嫁接
苦瓜
抗氧化系统
积累特征
cadmium
grafting
bitter gourd
antioxidant system
accumulation characteristics
