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Pre-harvest soybean seeds in the field are susceptible to high temperature and humidity (HTH) stress, leading to pre-harvest seed deterioration, which will result in a reduction in grain quality, yield, and seed vigor. To understand the gene expression involved in seed deterioration response under HTH stress, in this study, we conducted an RNA-Seq analysis using two previously screened soybean cultivars with contrasting seed deterioration resistance. HTH stress induced 1081 and 357 differentially expressed genes (DEGs) in the sensitive cultivar Ningzhen No. 1 and resistant cultivar Xiangdou No. 3, respectively. The majority of DEGs in the resistant cultivar were up-regulated, while down-regulated DEGs were predominant in the sensitive cultivar. KEGG pathway analysis revealed that metabolic pathways, biosynthesis of secondary metabolites, and protein processing in endoplasmic reticulum were the predominant pathways in both cultivars during seed deterioration under HTH stress. The genes involved in photosynthesis, carbohydrate metabolism, lipid metabolism, and heat shock proteins pathways might contribute to the different response to seed deterioration under HTH treatment in the two soybean cultivars. Our study extends the knowledge of gene expression in soybean seed under HTH stress and further provides insight into the molecular mechanism of seed deterioration as well as new strategies for breeding soybean with improved seed deterioration resistance. Key words: soybean, high temperature and humidity, RNA-Seq, pre-harvest seed deterioration. Avant la recolte, les graines de soja au champ sont sensibles a un stress cause par une temperature et une humidite elevees (HTH), ce qui peut entrainer une deterioration des grains en pre-recolte, laquelle diminue la qualite des grains, le rendement et la vigueur des graines. Pour comprendre les profils d'expression genique associes a cette deterioration en reponse au stress HTH, les auteurs ont realise une etude RNA-Seq sur deux cultivars prealablement identifies comme presentant une resistance contrastee a cette deterioration. Le stress HTH a permis d'identifier, respectivement, 1081 et 357 genes a expression differentielle (DEG) chez le cultivar sensible Ningzhen No. 1 et le cultivar resistant Xiangdou No. 3. La majorite des DEG chez le cultivar resistant etaient exprimes a la hausse, tandis que les genes moins fortement exprimes etaient predominants chez le cultivar sensible. Une analyse des sentiers KEGG a revele que les 'sentiers metaboliques', la 'biosynthese des metabolites secondaires' et la 'maturation des proteines dans le reticulum endoplasmique' etaient les sentiers predominants touches lors de la deterioration des graines soumis a un stress HTH. Les genes impliques dans la photosynthese, le metabolisme des hydrates de carbone, le metabolisme des lipides et les proteines de choc thermique pourraient contribuer a la reponse differente observee entre les deux cultivars soumis a un traitement de stress HTH. Cette etude accroit les connaissances sur l'expression genique chez les graines de soja en reponse au stress HTH et fournit un eclairage sur le mecanisme moleculaire de la deterioration des graines ainsi que sur de nouvelles strategies pour selectionner des sojas dotes d'une meilleure resistance a la deterioration des graines. [Traduit par la Redaction] Mots-cles : soja, temperature et humidite elevees, RNA-Seq, deterioration des graines en pre-recolte., Introduction Soybean seeds provide major sources of oil and protein globally for human consumption and animal feed (Saha and Sultana 2008). Seed quality is determined by its composition of protein, [...]