A research team in China has discovered a key japtropha gene that can boost yields and oil content, Phys.org wrote.
A perennial woody plant species that belongs to the Euphorbiaceae family, jatropha has potential as a biodiesel and bio-jet fuel feedstock due to its high oil content, high biomass productivity, adaptability to marginal lands under a variety of agro-climatic conditions and lack of competition with food production.
However, the potential of jatropha as a biofuel feedstock was limited by its low seed production, according to the researchers.
In the study published in Plant Biotechnology Journal on 23 January, researchers from the Chinese Academy of Sciences’ Xishuangbanna Tropical Botanical Garden (XTBG) highlighted the important role of the JcSPL9 gene, which belongs to the squamosa promoter binding protein-like (SPL) family, the 2 February Phys.org report said.
The gene acted as a master switch, controlling when the japtropha plant shifted from growing leaves to producing flowers and seeds.
Experiments showed that plants engineered to overexpress a modified form of JcSPL9 (called rJcSPL9) produced 80.76% more seeds and had 12.6% higher oil content compared to normal plants.
In contrast, boosting a related molecule called JcmiR156a led to a 51.67% drop in seed yield and an 8.28% decrease in oil content.
Further analysis revealed that rJcSPL9 turned on genes involved in oil production, while JcmiR156a turned them off, confirming that JcSPL9 enhanced oil accumulation by regulating metabolic pathways.
In addition, changes were found in the types of fatty acids produced in the seeds, indicating that the genetic mechanism affected oil composition.
“By using the rJcSPL9 and JcmiR156a transgenic jatropha, we demonstrate - for the first time - that SPL9 plays an important role in regulating fatty acid biosynthesis and lipid accumulation in seeds,” said Tang Mingyong from XTBG, one of the study’s corresponding authors.
The dual effect on yield and oil content made SPL9 a promising target for molecular breeding, the researchers said.
“JcSPL9 represents a promising tool for increasing seed yield, oil productivity and quality in jatropha, with potential applications to other oilseed crops,” added Mingyong.
