Transcriptional and proteomic insights into phytotoxic activity of interspecific potato hybrids with low glycoalkaloid contents.

We examined phytotoxic potential of diploid potato hybrids from 15-1 population. Individuals were bulked in bulks C and D. Both bulks characterized low total glycoalkaloids content and differ phytotoxic potential. Water extract prepared from leaves of individuals of bulk C inhibited growth of test plant - mustard in 40%, while in bulk D no inhibition was observed. To evaluate cause of expression of phytotoxic potential in bulk C, we examined glycoalklaoids composition in leaf water extract (mass spectrometry), compared gene (deep RNA sequencing - BGISEQ) and protein expression (nano-LC-MS-MS/MS) profiles between the bulks. Bulks differed in glycoalkaloids composition, bulk C contained alpha-solasonine which wasn't detected in bulk D. We concluded, alpha-solasonine may act together with alpha-solamargine and increases phytotoxic potential of leave extract of bulk C. Comparison of gene expression profiles indicating on contribution of genes, not directly involved in glycoalkaloids biosynthesis to express phytotoxic potential of C bulk. We have found 3 proteins characteristic for C bulk and 2 proteins characteristic for D bulk. We found one protein threonine dehydratase biosynthetic, which is more abundant in D bulk and his abundance corresponds with gene transcripts found in RNA-seq experiment. Examination of potato phytotoxic potential under low glycoalkaloids content.

本研究针对15-1群体的二倍体马铃薯杂交种的植物毒性潜力展开了探究。供试个体被分为C、D两个混合样组。两个混合样组的总糖苷生物碱（glycoalkaloids）含量均较低，但植物毒性潜力存在显著差异。从C组个体叶片制备的水提液可使受试植物——芥菜的生长受到40%的抑制，而D组水提液未表现出抑制效果。为解析C组植物毒性潜力的表达机制，本研究通过质谱（mass spectrometry）分析了叶片水提液中的糖苷生物碱组成，并借助BGISEQ平台的深度RNA测序（deep RNA sequencing）以及纳米液相色谱-串联质谱联用（nano-LC-MS-MS/MS）技术，对比了两个混合样组的基因与蛋白质表达谱。两个混合样组的糖苷生物碱组成存在差异：C组含有α-澳洲茄边碱（alpha-solasonine），而D组未检出该成分。本研究推断，α-澳洲茄边碱可与α-澳洲茄碱（alpha-solamargine）协同作用，提升C组叶片水提液的植物毒性潜力。基因表达谱对比结果显示，并非直接参与糖苷生物碱生物合成的基因，也对C组的植物毒性潜力表达具有贡献。本研究分别鉴定出C组特有的3种蛋白质与D组特有的2种蛋白质。我们发现了一种苏氨酸脱水酶（threonine dehydratase）生物合成相关蛋白，该蛋白在D组中的丰度更高，且其丰度与RNA-seq实验中检测到的基因转录本水平相一致。本研究针对低糖苷生物碱含量条件下马铃薯的植物毒性潜力展开了探究。