低硼及高硼胁迫对棉花幼苗生长与脯氨酸代谢的影响  

Effects of boron deficiency/toxicity on the growth and proline metabolism of cotton seedlings

作　　者：曾紫君 曾钰 闫磊[1] 程锦 姜存仓[1] ZENG Zi-Jun;ZENG Yu;YAN Lei;CHENG Jin;JIANG Cun-Cang(College of Resources and Environment,Huazhong Agricultural University/Microelement Research Center,Wuhan 430070,Hubei,China)

机构地区：[1]华中农业大学资源与环境学院/微量元素研究中心,湖北武汉430070

出　　处：《作物学报》2021年第8期1616-1623,共8页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(41271320);中央高校基本科研业务费专项资金项目(2017PY055)资助。

摘　　要：以‘鄂抗10号’棉花品种为材料,采用营养液培养,设置不加硼(B0,0 mg L^(-1))、低硼(B0.002,0.002 mg L^(-1))、适硼(CK,B0.2,0.20 mg L^(-1))、高硼(B50,50 mg L^(-1))4个硼(Boron,B)水平,探究低硼和高硼胁迫处理下棉花幼苗生长及脯氨酸代谢的响应。结果表明,B0、B0.002及B50处理较CK显著抑制植株生长,表现出较低的植株鲜重和干重,根系伸长受到抑制。在供硼处理下,随着硼浓度的升高,棉花幼苗根、茎和叶中硼含量均呈梯度性上升,其中,B0.2和B50处理下叶片中硼含量均高于根和茎;而在B0和B0.002处理下,根中的硼含量高于叶和茎。低硼和高硼处理下叶片中脯氨酸含量明显增加,而根中脯氨酸含量显著减少。进一步分析叶片和根中脯氨酸合成代谢相关酶活性发现,B0.002和B50处理较CK增加棉花幼苗叶片Δ1-吡咯啉-5-羧酸合成酶(Δ1-pyrroline-5-carboxylate synthetase,P5CS)和鸟氨酸转氨酶(Ornithine-δ-aminotransferase,OAT)活性而降低脯氨酸脱氢酶(Proline dehydrogenase,ProDH)的活性;叶片中Δ1-吡咯啉-5-羧酸还原酶(Δ1-pyrroline-5-carboxylate reductase,P5CR)活性在B50处理下显著高于CK,而B0.002处理下该酶活性变化差异不显著。另外,B50处理较CK显著降低棉花幼苗根中OAT和P5CR酶活性,而B0.002处理显著增加根中P5CS和ProDH的活性。表明低硼和高硼胁迫均抑制棉花幼苗的生长。硼胁迫条件下,脯氨酸主要积累在棉花幼苗叶片中,根中脯氨酸含量显著降低。缺硼和硼毒害时,棉花幼苗叶片中脯氨酸的积累主要是通过调节脯氨酸Glu和Orn途径中的关键酶(OAT、P5CS合成酶和ProDH分解酶)活性,使得脯氨酸的合成速度高于其降解。而在根中,缺硼胁迫下主要是促进脯氨酸的降解导致根中脯氨酸含量降低,高硼胁迫下主要是通过降低OAT和P5CS合成酶以及ProDH分解酶活性来抑制脯氨酸的合成及其分解,但是对脯氨酸合成的抑制作用远大于其降解,最终导致�To investigate the response of cotton seedlings growth and proline metabolism to low-and excess-boron stress treatment conditions,the experiment was conducted using‘E kang 10’as experimental material using hydroponic method in a greenhouse of Huazhong Agricultural University.Boron(B)were applied at four levels at 0 mg L^(-1)(B0,no boron),0.002 mg L^(-1)(B0.002,low concentration boron),0.20 mg L^(-1)(B0.2,CK,sufficient concentration boron),and 50 mg L^(-1)(B50,high concentration boron).The results showed that B0,B0.002,and B50 treatments significantly decreased the fresh and dry weights of plants,and inhibited root elongation relative to sufficient boron(CK,B0.2)treatment.With the increase of B concentration,B content in roots,stems,and leaves of cotton seedlings increased gradiently.Among them,B contents in the leaves under B0.2 and B50 treatments were higher than those in roots and stems,while B content in the roots was increased in leaves and stems under B0 and B0.002 treatments.Under low-and high-boron stress treatments,the content of proline in leaves increased dramatically,while proline in roots decreased.Further analysis of related enzyme activities in proline metabolism,we found that B0.002 and B50 treatments promoted the activities ofΔ1-pyrroline-5-carboxylate synthetase(P5CS)and ornithine-δ-aminotransferase(OAT)in leaves,but decreased the activity of proline dehydrogenase(ProDH)compared to CK;and the activity ofΔ1-pyrroline-5-carboxylate reductase(P5CR)in leaves under B50 treatment was obviously increased,but there was no significant difference under B0.002 treatment.In addition,compared with CK,B50 treatment reduced the enzyme activities of OAT and P5CR in roots,while B0.002 treatment prominently increased the activities of P5CS and ProDH.The results showed that both low-and excess-boron stress inhibited the growth of cotton seedlings.Under boron stress,proline mainly was accumulated in the leaves of cotton seedlings,and the content of proline in roots decreased significantly.In the case of boron

关 键 词：棉花 硼 脯氨酸 合成和降解 

分 类 号：S562[农业科学—作物学]