Molecular and physiological adaptation to prolonged drought stress in the leaves of two Andean potato genotypes

Abstract

Responses to prolonged drought and recovery from drought of two South American potato (Solanum tuberosum L. ssp. andigena (Juz & Buk) Hawkes) landraces, Sullu and Ccompis were compared under field conditions. Physiological and biomass measurements, yield analysis, the results of hybridisation to a potato microarray platform (44 000 probes) and metabolite profiling were used to characterise responses to water deficit. Drought affected shoot and root biomass negatively in Ccompis but not in Sullu, whereas both genotypes maintained tuber yield under water stress. Ccompis showed stronger reduction in maximum quantum yield under stress than Sullu, and less decrease in stomatal resistance. Genes associated with PSII functions were activated during recovery in Sullu only. Evidence for sucrose accumulation in Sullu only during maximum stress and recovery was observed, in addition to increases in cell wall biosynthesis. A depression in the abundance of plastid superoxide dismutase transcripts was observed under maximum stress in Ccompis. Both sucrose and the regulatory molecule trehalose accumulated in the leaves of Sullu only. In contrast, in Ccompis, the raffinose oligosaccharide family pathway was activated, whereas low levels of sucrose and minor stress-mediated changes in trehalose were observed. Proline, and expression of the associated genes, rose in both genotypes under drought, with a 3-fold higher increase in Sullu than in Ccompis. The results demonstrate the presence of distinct molecular and biochemical drought responses in the two potato landraces leading to yield maintenance but differential biomass accumulation in vegetative tissues.

Effects of Drought on Gene Expression in Maize Reproductive and Leaf Meristem Tissue Revealed by RNA-Seq

“…Thus, scavenging of ROS through the action of antioxidant genes encoding enzymes that reside in the mitochondrion and the cytosol appears to be curtailed under drought stress in the ovary, whereas the drought stress did not have this effect on antioxidant gene expression in leaf meristem, where antioxidant defenses occurred, as has been observed many times, in many tissues, and in many species. An analogous decrease in the expression of antioxidant genes was observed in a more drought-susceptible accession of Andean potato when compared with patterns of gene expression in a more drought-tolerant accession (Mane et al, 2007(Mane et al, , 2008. Interestingly, catalase and peroxisomal APX showed increased expression in the stressed ovary, which is the more expected response to drought (Supplemental Table S3).…”

El camino de la biotecnología en la Universidad Nacional Agraria La Molina, Perú

“…César López y M.Sc. Roberto Mansilla) y de la Facultad de Agronomía (Dr. Raúl Blas, profesor del PDCIB) en el área de plantas realizan investigaciones en marcación molecular de especies nativas (Blas et al 2008, Blas & Petrescu 2009, Mane et al 2008, de la Torre et al 2008. Igualmente, el grupo de la Facultad de Industrias Alimentarias conformado por el Dr. David Campos, la Dra.…”

Recent advances in potato genomics, transcriptomics, and transgenicsunder drought and heat stresses: a review

“…Moreover, higher levels of osmolyte accumulation, such as galactose, inositol, galactinol, and proline, were observed in Sullu under drought stress, suggesting the tolerance mechanisms of tolerant clone Sullu became less pronounced in this field water withholding study, while it could still produce three times higher tuber yields compared to the sensitive clone SS2613. In another attempt to relate the transcriptomic differences between potato accessions, accessions Sullu and Ccompis were compared under drought conditions in a field at high altitude (Mane et al, 2008). Sullu was found to tolerate water withdrawal better compared to Ccompis since the expression levels of genes involved in antioxidant, flavonoid, and carbohydrate metabolisms were higher in Sullu, indicating the presence of distinct molecular and biochemical drought responses in the two potato accessions leading to yield maintenance but differential biomass accumulation in vegetative tissues.…”