UoH finds gene that helps tomato plants reuse phosphate

Researchers at the University of Hyderabad (UoH) have identified a molecular mechanism that helps tomato plants move stored phosphate from older leaves to younger tissues. The study, published in the Journal of Experimental Botany, was led by Prof Rahul Kumar and Abhishek Roychowdhury, with collaborators from Mendel University and the Spanish National Research Council (CSIC).

The team found that the tomato gene SlPAP26b drives phosphate remobilisation. When the gene was silenced, older leaves lost their ability to transfer phosphate, triggering a starvation response in younger leaves and roots even under normal nutrient conditions. The response involved the master regulator SlPHL1 and microRNA miR399, while older leaves remained unaffected, showing that different leaf nodes maintain distinct phosphate signalling mechanisms.

The discovery identifies the SlSPX2-SlPHL1 regulatory pathway as a genetic target for improving phosphate use efficiency. Researchers say manipulating this mechanism could lead to resilient crop varieties that reduce dependence on chemical fertilisers, cutting farmer input costs and limiting soil degradation.

Update, 7 October 2026: The New Indian Express now also reports the discovery, naming SlPAP26b as the key regulator and adding that the research involved collaborators from Mendel University and the Spanish National Research Council (CSIC). It also specifies that the transcription factors SlPHR1 and SlPHL1 activate the gene by binding to the P1BS element in its promoter.