Periódicos Brasileiros em Medicina Veterinária e Zootecnia

p. 509-516

Root growth and lignification of glyphosate susceptible and resistant soybean at low temperatures

da Costa Zonetti, PatriciaSayuri Suzuki DOliveira, LeticiaAparecida Bonini, Edicleiade Lourdes Lucio Ferrarese, MariaFerrarese-Filho, Osvaldo

Low temperature stress affects plant growth, including primary and secondary metabolism. Glyphosateresistant soybean contains a modified DNA, which encodes a different type of secondary metabolism enzyme related to lignin synthesis compared to conventional glyphosate-susceptible cultivars. Thus, this soybean cultivar might respond differently to low temperatures, compared to glyphosate-susceptible cultivars. This work aimed to investigate how decreasing temperatures influence the growth and lignin content of the glyphosate-resistant soybean compared to its susceptible parental cultivars. Three-day-old seedlings were cultivated in nutrient solution at 10, 15, 20, and 25C (±2C), using a 12-h photoperiod. After 96 h, taproot growth, fresh and dry biomass, and lignin levels were determined. The results indicate that lower temperatures decreased seedling and root growth in both types of cultivars; however, glyphosate-resistant soybean exhibited greater root length, biomass, and lignin content compared to the glyphosate-susceptible parental cultivar.

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