Pineapple genome offers insight into drought-tolerant plants

 

The production of pineapples began in 

southwest Brazil and northeast Paraguay. Pineapples have been cultivated by humans for more than six-thousand years and are now produced in more than eighty-five countries. In a recent study, scientists are homing in on the genes and the genetic pathways which allow the pineapple plant to prosper in environments that are water-limited by sequencing the juicy plant’s genome. Similar to many plants, the ancestors of pineapple and grasses experienced several doublings of their genomes. Although, the analysis shows that unlike the grasses that share an ancestor with pineapple, the pineapple genome has one-less whole genome duplication. This information indicated that pineapple plant is the best comparison group for the study of cereal crop genomes. Overall, the findings provided evidence of two-whole genome duplications in the pineapple plant’s history and a new opening on the evolutionary history of grasses. 

A majority of crop plants make use of a type of photosynthesis called C3. The juicy pineapple plant uses a special type of photosynthesis, called crassulacean acid metabolism, also known as CAM. CAM has evolved in more than ten-thousand plant species independently and the pineapple plant is valued the most economically out of all ten-thousand. Biology professor Ray Ming states “CAM plants use only 20 percent of the water used by typical C3 crop plants, and CAM plants can grow in dry, marginal lands that are unsuited for most crop plants.” By looking more closely at the pineapple genome, it was revealed that some genes which contribute to CAM photosynthesis are actually regulated by the plants circadian clock genes. Circadian clock genes allow plants to distinguish between day and night and alter their metabolism as a result. 

This study allowed scientists to find a link among regulatory elements of CAM photosynthesis genes and the circadian clock regulation for the first time. “CAM photosynthesis allows plants to close the pores in their leaves during the day and open them at night,” states Professor Ming, illustrating how that contributes to the pineapple plant’s resilience in hot climates and that the plant loses very little moisture through its leaves during the course of the day. CAM plants greatly reduce water loss by keeping their stomata closed during the day.

The team involved in this study wrote “All plants contain the necessary genes for CAM photosynthesis and the evolution of CAM simply required rerouting of pre-existing pathways.” The team is responsible for the discovering in which CAM photosynthesis evolved by reconfiguring molecular pathways involved in C3 and CAM photosynthesis. 

Having many farmers within the family and understanding how devastating a drought can be for the crops and overall production for that year, this article was attention-grabbing. The scientists now look to use their understanding of the evolution of the different types of photosynthesis in effort to develop drought-tolerant crops. “Higher water-use efficiency is a highly desirable trait, given the need to double food production by 2050 in the context of a changing climate,” stated Ray Ming. Furthermore, the adaptation of food crops to be more tolerant of a drought will also help humans become accustomed to climate change. 

Original Article