ABSTRACT
Stay-green trait and its potential for durum wheat breeding under water and heat stress conditions: A review

Matias Valenzuela1, Javier Chandia1, Miguel Garriga1, Ivan Matus2, and Dalma Castillo2*
 
Durum wheat (Triticum turgidum ssp. durum) is the second-most cultivated species of wheat worldwide, being mostly used for the production of semolina for pasta products. Drought and high temperatures can seriously affect the crop by accelerating senescence and decreasing yield and grain quality, thereby posing risks to food security on a global scale. Certain wheat genotypes exhibit a stay-green trait that enables plants to delay senescence and maintain photosynthetic activity longer. Thus, stay-green plants have an extended grain filling stage, which results in higher yields. Key genes associated with the stay-green trait, such as SGR1 and SGR2, help delay chlorophyll degradation, extending photosynthesis. Additionally, microRNAs (miRNAs) like miR164 and miR319 play a key role in regulating senescence and stress responses in plants. Technologies such as RNA sequencing (RNA-Seq) have been valuable tools for identifying differentially expressed genes associated with photosynthesis and stress resilience, providing valuable information for the development of more resilient durum and bread wheat varieties in wheat breeding programs. The present review provides insights into the advances and importance of the molecular and metabolic characterization of the stay-green trait in durum wheat and aims to get a better understanding of the effect of mRNAs and miRNAs on this trait under water and heat stress conditions.
Keywords: Drought, heat, QTL, stay-green, stress resilient wheat.
1Universidad de Concepcion, Facultad de Agronomia, Chillan, Chile.
2Instituto de Investigaciones Agropecuarias, INIA Quilamapu, Chillan, Chile.
*Corresponding author (dalma.castillo@inia.cl).