Comparative Paraquat Sensitivity of Newly Germinated and Mature Fronds of the Aquatic Macrophyte <i>Spirodela polyrhiza</i>

• 作者: Hojun Lee Jihae Park Taejun Han
• 来源期刊: 美国植物学期刊(英文)
• 学科: 数学
• 关键词: Spirodela polyrhiza PARAQUAT HERBICIDE Chlorophyll Contents Chlorophyll a Fluorescence Root Length
• 年，卷（期）: mgzwxqkyw_2020,（7）
• 页码范围: 1008-1024
• 页数: 17页
• 分类号: O17

摘要

Here, we compared the intrinsic characteristics of 3-day-(newly germinated;<span><span style="font-family:Verdana;">“young”) and 8-week-old (“mature”) fronds of the aquatic plant </span><i><span style="font-family:Verdana;">Spirodela</span></i><span style="font-family:Verdana;"> <i>polyrhiza</i></span> </span><span style="font-family:Verdana;">and their sensitivity to paraquat, a toxic herbicide. Endpoints measured were frond area and fresh weight, root length, chlorophyll</span><i><span style="font-family:Verdana;"> a</span></i><span style="font-family:Verdana;"> and</span><i><span style="font-family:Verdana;"> b </span></i><span style="font-family:Verdana;">contents, and chlorophyll</span><i><span style="font-family:Verdana;"> a</span></i><span style="font-family:Verdana;"> fluorescence. Significant differences were detected in the intrinsic physiological traits between young and mature fronds. Young fronds showed higher root length, chlorophyll contents, maximum quantum yield (</span><i><span style="font-family:Verdana;">F</span>_{<span style="font-family:Verdana;">v</span>}</i><span style="font-family:Verdana;">/</span><i><span style="font-family:Verdana;">F</span>_{<span style="font-family:Verdana;">m</span>}</i><span style="font-family:Verdana;">), maximal relative electron transport rate (rETR</span>_{<span style="font-family:Verdana;">max</span>}<span style="font-family:Verdana;">) and saturating photon flux density (PFD), whereas mature fronds exhibited greater frond area and fresh weight. After a 72 h exposure to paraquat, root length and rETR</span>_{<span style="font-family:Verdana;">max</span>}<span style="font-family:Verdana;"> were identified as the most sensitive endpoints of paraquat toxicity for both frond types, with EC</span>_{<span style="font-family:Verdana;">50</span>}<span style="font-family:Verdana;"> values of 0.66 and 0.76 μg<span style="font-size:6.5pt;font-family:"background:yellow;">&middot;</span>L</span><sup><span style="font-family: