Cho Eunjin, Gurdon Csanad, Zhao Rebecca, Peng Hui, Poulev Alexander, Raskin Ilya, Simko Ivan
Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA.
Crop Improvement and Protection Research Unit, US Department of Agriculture, Agricultural Research Service, Salinas, CA 93905, USA.
Plants (Basel). 2023 Oct 2;12(19):3467. doi: 10.3390/plants12193467.
Flavonoids are antioxidant phytochemicals that confer a beneficial effect on human health. We have previously developed and characterized eight lettuce ( L.) lines that accumulated high levels of diverse flavonoids and their precursors in controlled environment conditions. Three Rutgers Scarlet lettuce (RSL) lines selected in tissue culture for deep-red color (RSL-NAR, RSL-NBR, RSL-NFR) accumulate anthocyanins and quercetin, three lines identified in a chemically mutagenized red lettuce population accumulate kaempferol (KfoA and KfoB) or naringenin chalcone (Nco), and two lines that were spontaneous green mutants derived from the red line RSL-NAR (GSL, GSL-DG) accumulate quercetin. These eight lines were field-grown in the Salinas Valley of California for four years together with seven control accessions of varying colors (light green, dark green, red, and dark red). At market maturity, a substantial variation in plant composition was observed, but the three RSL lines consistently accumulated high levels of cyanidin, GSL and GSL-DG accumulated the highest levels of quercetin, KfoA and KfoB accumulated kaempferol, and Nco amassed naringenin chalcone, confirming that these mutant lines produce high levels of beneficial phytochemicals under field conditions. Mutant lines and control accessions were also assessed for their biomass production (plant weight, height, and width), overall content of pigments (leaf chlorophyll and anthocyanins), resistance to diseases (downy mildew, lettuce drop, and Impatiens necrotic spot virus), postharvest quality of processed tissue (deterioration and enzymatic discoloration), and composition of 23 mineral elements. All but one mutant line had a fresh plant weight at harvest comparable to commercial leaf cultivars; only Nco plants were significantly ( < 0.05) smaller. Therefore, except for Nco, the new, flavonoid hyperaccumulating lines can be considered for field cultivation.
类黄酮是具有抗氧化作用的植物化学物质，对人体健康有益。我们之前已培育并鉴定出8个生菜（L.）品系，它们在可控环境条件下能积累高水平的多种类黄酮及其前体。在组织培养中筛选出的3个深红色罗格斯红生菜（RSL）品系（RSL-NAR、RSL-NBR、RSL-NFR）积累花青素和槲皮素，在化学诱变的红色生菜群体中鉴定出的3个品系积累山奈酚（KfoA和KfoB）或柚皮素查尔酮（Nco），以及从红色品系RSL-NAR自发产生的2个绿色突变体系（GSL、GSL-DG）积累槲皮素。这8个品系与7个不同颜色（浅绿、深绿、红色和深红色）的对照种质一起在加利福尼亚州的萨利纳斯山谷进行了4年的田间种植。在市场成熟期，观察到植株组成存在显著差异，但3个RSL品系始终积累高水平的矢车菊素，GSL和GSL-DG积累的槲皮素水平最高，KfoA和KfoB积累山奈酚，Nco积累柚皮素查尔酮，这证实了这些突变体系在田间条件下能产生高水平的有益植物化学物质。还对突变体系和对照种质的生物量生产（植株重量、高度和宽度）、色素总含量（叶片叶绿素和花青素）、抗病性（霜霉病、生菜萎蔫病和凤仙花坏死斑病毒）、加工组织的采后品质（变质和酶促变色）以及23种矿质元素的组成进行了评估。除一个突变体系外，所有突变体系收获时的鲜重均与商业叶用品种相当；只有Nco植株明显（<0.05）较小。因此，除Nco外，新的类黄酮超积累品系可考虑用于田间种植。
