杉木根边缘细胞生物学特性及其对铝胁迫的响应  

Biological Characteristics and Response to Aluminum Stress of Root Border Cells in Cunninghamia lanceolata and Their Response to Aluminum Stress

作　　者：李舟阳 陆文玲 钱旺 黄奕孜 林二培[1] 黄华宏[1] 童再康[1] Li Zhouyang;Lu Wenling;Qian Wang;Huang Yizi;Lin Erpei;Huang Huahong;Tong Zaikang(State Key Laboratory of Subtropical Silviculture,Zhejiang A&F University,Hangzhou 311300)

机构地区：[1]浙江农林大学亚热带森林培育国家重点实验室,杭州311300

出　　处：《林业科学》2022年第7期73-81,共9页Scientia Silvae Sinicae

基　　金：浙江省重点研发计划项目(2021C02054)。

摘　　要：【目的】分析杉木根边缘细胞的生物学特性及其对铝胁迫的响应,为进一步研究杉木对铝胁迫的响应机制和耐铝种质筛选提供参考。【方法】利用悬空气培法研究不同根长杉木幼苗根边缘细胞的数量、活性等生物学特性,并通过铝离子处理分析杉木根边缘细胞对铝胁迫的响应。【结果】杉木种子刚萌发时,根尖处就开始产生边缘细胞,且边缘细胞数量随着根的伸长而逐渐增多,在根长1.5 cm时达到最大值,平均7497个。边缘细胞活性在根长小于0.5 cm时可达95%,随着根的伸长会逐渐降低,但基本稳定在80%左右。在根边缘细胞发育过程中,根冠果胶甲酯酶(PME)活性随着根的伸长呈现出先高后低的趋势,进一步的表没食子儿茶素没食子酸酯(EGCG)处理表明PME活性与边缘细胞游离至根际环境有关。铝胁迫处理结果表明,铝离子会显著抑制杉木幼苗根的伸长,且这种抑制作用在擦除根边缘细胞后会更加明显;低浓度的铝离子(100-200μmol•L^(-1))会促使边缘细胞分泌更多黏液,黏液层阻止铝离子吸附在根尖部位,从而对根尖起到一定保护作用。【结论】杉木幼苗根尖会产生大量具有活性的边缘细胞,其游离至根际环境的过程可能主要受到PME酶的调控;这些根边缘细胞会对铝离子胁迫作出响应,分泌更多黏液,从而起到减轻铝毒害或保护根尖免受铝毒害的作用。【Objective】This study aims to investigate the biological characteristics of root border cells of Cunninghamia lanceolata and their response to aluminum stress,which could provide important basis for elucidation of response to aluminum stress and selection of aluminum-tolerant germplasms in C.lanceolata.【Method】In this study,seeds of C.lanceolata were germinated through aeroponic culture methid.The biological characteristics of root border cells were investigated with the seedlings of C.lanceolata.The response of root border cells to aluminum stress was also surveyed by aluminum ion treatment.【Result】It was found that the root tip began to be produced root border cells when the seeds just germinated,and the number of root border cells gradually increased with the elongation of the roots.When the root length was 1.5 cm,the number of root border cells reached the maximum(about 7497 in average).The cell activity test showed that when the root length was less than 0.5 cm,the activity of root border cells could reach 95%.With the elongation of roots,the activity of root border cells decreased gradually,but basically stabilized around 80%.During the development of root border cells,the activity of pectin methylesterase(PME)in root cap showed its highest level when root length less than 0.5 cm,and then decreased with the root elongation.And,further EGCG treatment indicated that the PME activity was not required for the formation of root border cells but rather related to their spatial separation.The results of aluminum stress showed that Al^(3+) was able to significantly inhibit the root elongation of C.lanceolata seedlings,and this inhibition effect was more obvious after removal of the root border cells.Low concentration of Al^(3+)(100-200μmol•L^(-1))promoted root border cells to secrete more mucilage and form a thicker mucilage layer,which prevented Al^(3+) from adsorbing to the root tips and thus played a protective role for the root tips.【Conclusion】The root tips of C.lanceolata seedlings can prod

关 键 词：杉木 根边缘细胞 果胶甲酯酶 铝胁迫 

分 类 号：S791[农业科学—林木遗传育种]