Análisis genómicos por RT-qPCR de expresión diferencial de genes de adaptación a sequía en las variedades Chenopodium quinoa seleccionadas (Bolivia y Ecuador) en condiciones control y sequía

Abstract

Nowadays, increasingly common periods of drought due to climate change pose a challenge to agricultural production. The propagation and coordination of the drought response in plants is carried out by signaling molecules whose pathways allow the activation of drought response genes as well as stomatal regulation. In addition, recent studies point out that these signaling elements, such as phytohormones, can trigger changes in the metabolism of cell wall components (such aspectins and xyloglucans) in adaptation to water stress.

On the other hand, quinoa (Chenopodium quinoa Wild.) is a halophilic plant native to the Andes that provides a food of high nutritional value. In recent years, this crop has gained international attention and has been named a ”key crop for food security and sustainability under climate change” by the FAO. Therefore, elucidating drought adaptation mechanisms in quinoa could prove very useful in the face of challenges posed to agricultural production by drought.

In this work, the differential expression of drought adaptation genes was evaluated by One-Step RT-qPCR in 5 selected varieties C. quinoa. For this purpose, drought adaptation genes related to molecular pathways and cell wall metabolism were selected: SnRK2, HSP70, PME and XTH. In addition, the varieties were phenotypically characterized, the evapotranspiration rate of each was analyzed, and the effect of drought on plant photosynthetic capacity was evaluated. Gene expression data were explored using unsupervised machine learning algorithms. Finally, the analyses were also carried out on the wild relatives C. album and C. botrys.

Our results show that, differential expression of SnRK2 and HSP70 against drought have different behaviours depending on quinoa variety. On the other hand, in general, the expression of PME and XTH genes increases in the adaptation to drought. In particular, PME shows high expression, so pectin matrix remodeling seems to be a relevant mechanism against drought in quinoa.