Transgenic NAC Arabidopsis Phenotyping for Senescence Process

BENGOA LUONI, S.; FERNANDEZ , P.; VILE, D.

Conferencia; Second International Meeting of Women in Bioinformatics; 2021

Leaf senescence is a complex mechanism ruled by multiple genetic and environmental variables that affect crop yields. It is the last stage in leaf development and is characterized by an active decay in photosynthetic rate, nutrients recycling and cell death.In annual plants, such as grain and oil crops, flowering induces senescence accompanied by nutrient remobilization from leaves to developing seeds. Prematurely induced senescence can reduce crop yield. Thus, leaf senescence has an economic impact and affects the potential and real yields gap.Sunflower (Helianthus annuus L.) is the third most important source of edible vegetable oil worldwide and the second in Argentina. This crop also provides an important source of biodiesel. Although not available yet, the full sequence will be available soon (http://sunflowergenome.org/early_access/repository/main/genome/index.html) thanks to recent studies that generated genomic information on this crop.. However, functional genomics tools for cultivated sunflower have been developed, including transcriptional and metabolic profiling strategies as well as integrated bioinformatics analysis Sunflower is an annual monocarpic species in which reproductive organs exert a strong control on leaf senescence and nutrient remobilization, affecting grain weight by the source:sink ratio. The age of a leaf and its position on the stem also affect the triggering of senescence and the rate of nutrient remobilization Moreover, a delay in senescence has a great impact in grain weight and yield of important crops due to the maintenance of photosynthetically active leaf area during reproductive stage, including sunflower. Hence, grain filling percentage per capitulum is a component that contributes to overall yield of sunflower crop and it might be increased in crops that retain its photo synthetically leaf area for a longer period of time. This finding emphasizes the need to search for mutants that retain leaf greenness, also known as stay-green genotypes. Functional stay-green shows delayed leaf senescence onset or altered senescence rate maintaining photosynthetic activity for longer periods, while cosmetic stay-green decreases the photosynthetic