The DNAJ gene family in yerba mate (Ilex paraguariensis): genome-wide identification, structural characterization, orthology based classification and expression analysis

Abstract Dry leaves and twigs of yerba mate are widely infusion-consumed in southern Southamerica. Endemic and adapted to the Atlantic Forest, its extensive full-sun monoculture links to diverse biotic (pest, pathogens) and abiotic stresses (solar radiation, drought), impacting its productivity, ecology and socioeconomic niche. We focused in comprehensively characterize the DNAJ gene family in yerba mate to predict its possible roles on development and diverse stress responses to further assist crop manage. Our results suggest that yerba mate DNAJ proteins account 140 diverse members of six structural types displaying potential variable roles in protein homeostasis control. We were able to classify them into 51 distinct orthology groups, in agreement to Arabidopsis, and performed translational genomics of function, localization, expression and stress responsiveness data. Genome mapping and expression analysis indicated that yerba mate DNAJ genes differ in expression, nucleotide composition, length and exon-intron structure. Intronless or few introns genes -linked to rapid stress response- accounted 85 DNAJs. Promoters of DNAJ genes harbored a 73.2% of cis-acting regulatory elements involved in response to diverse stresses, hormones and light, simultaneously. We hypothesize that yerba mate DNAJs assist to plant survival during multiple stresses linked to current dominant agroecosystem but promote its growth under shade.摘要 马黛茶（yerba mate）的干燥叶片与枝条在南美南部被广泛用于冲泡饮用。作为大西洋森林特有物种且适配该生境，其大规模全光照单一种植模式会伴随多种生物胁迫（虫害、病原菌侵染）与非生物胁迫（太阳辐射、干旱），进而对其生产力、生态特征及社会经济种植价值产生影响。本研究聚焦于全面解析马黛茶的DNAJ基因家族（DNAJ gene family），以预测其在植物发育与多种胁迫响应中的潜在功能，为作物管理提供辅助依据。 研究结果表明，马黛茶的DNAJ蛋白包含140个结构类型多样的成员，分属6个结构类别，在蛋白质稳态调控中可能发挥多样化作用。我们将这些蛋白划分为51个独立的直系同源组，该分类结果与拟南芥（Arabidopsis）的分类结果一致；同时完成了功能、亚细胞定位、表达模式及胁迫响应相关数据的翻译基因组学分析。 基因组定位与表达分析显示，马黛茶的DNAJ基因在表达水平、核苷酸组成、序列长度及内含子-外显子结构上均存在差异。其中85个DNAJ基因不含内含子或仅含少量内含子，这类基因通常与快速胁迫响应相关。DNAJ基因的启动子区域中，73.2%的顺式作用调控元件（cis-acting regulatory elements）可同时响应多种胁迫、激素及光照信号。 我们推测，马黛茶DNAJ家族可协助植物在当前主流农业生态系统带来的多重胁迫下存活，并促进植株在遮阴环境下的生长。