PILS6 is a temperature-sensitive regulator of nuclear auxin input and organ growth (PNAS)

Auxin, a plant hormone and major growth regulator, is fundamental for adaptations to climatic variation in shoots but its role in roots under elevated temperatures is more controversial. PIN-LIKES (PILS) 2, 3 and 5 proteins have previously been identified to restrict nuclear auxin signalling but the role of PILS6 is less studied. Here, by developing PILS6 gene knockout plants, Feraru et al. demonstrated that the protein functions as a negative regulator in auxin accumulation and perception in the endoplasmic reticulum. Furthermore, under high temperatures (>27^oC) the abundance of PILS6 decreases allowing for increased nuclear auxin signaling, leading to promoted root growth. The authors conclude that PILS proteins are important for abiotic adaptations and their identification is a significant step in understanding how rising ambient temperatures will affect plant development and growth (Summary by Alex Bowles) PNAS 10.1073/pnas.1814015116.