Seedlings of two Sorghum bicolor show different water management strategies when exposed to salt or water deficit condition

MOIRA SUTKA; VICTORIA VITALI; MILENA MANZUR; GABRIELA AMODEO

Foz de Iguazú

Congreso; 11t Inetnational Congress of Plant Molecular Biology; 2015

Sorghum [Sorghum bicolor (L.) Moench.] is an ancient tolerant crop with potential to sustain high yields in adverse environmental conditions, a feature on the rise due to climate changes. Understanding the performance of this species in early phenological stages could be a useful tool for future yield improvement programs. The aim of this work was to compare the response of sorghum seedlings under water deficit or salt stress conditions in two genotypes employed in our country: RedLandB2 and IS9530. In particular we analyzed water adjustment capacity at the whole plant level. As expected, in treated seedlings there is a drop in water potential values but only seedlings from both genotypes exposed to salt reduces their leaf osmotic potential component similarly. The decrease in water potential is consistent with a reduction in root hydraulic conductivity (Lpr) under water deficit condition but not under salt stress, where only RedLandB2 shows an inhibition of Lpr. Relative water content is only affected in the IS9530 genotype independently of the source of stress. Stomatal conductance was not coupled and showed a distinguishable behavior not only in terms of the sources of stress (salt versus water deficit) but also in terms of genotype (RedLandB2 versus IS9530). Interestingly, these different strategies do not necessarily impact in biomass reallocation, which remains as a conserved trait that affects similarly plant development in both genotypes. Our result provides a complementary insight of water management in terms of anisohydric and isohydric behavior that can be developed by a stress tolerant crop.