Vol.:(0123456789) 1 3 Planta https://doi.org/10.1007/s00425-019-03237-9 ORIGINAL ARTICLE Phosphate supply infuenced the growth, yield and expression of PHT1 family phosphate transporters in seven millets Theivanayagam Maharajan 1  · Stanislaus Antony Ceasar 1,2  · Thumadath Palayullaparambil Ajeesh Krishna 1  · Savarimuthu Ignacimuthu 1 Received: 7 June 2019 / Accepted: 9 July 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Main conclusion Phosphate starvation altered the root morphology and phosphate uptake with the induction of PHT1 family transporter genes in root and shoot tissues of seven millets. Abstract Millets are nutrient-rich cereals majorly cultivated in Asia and Africa. Foxtail millet (FoxM), pearl millet (PeaM), fnger millet (FinM), kodo millet (KodM), little millet (LitM), proso millet (ProM), and barnyard millet (BarM) were exam- ined for the infuence of external phosphorous (P) supply on phenotypic traits, P uptake, yield, and PHosphate Transporter1 (PHT1) family gene expression. Millet seedlings grown under low Pi condition (LPC) produced signifcantly lower mean values for all traits except for lateral root length (LRL) and lateral root number (LRN) which were increased under LPC. Under LPC, seed weight (SW) also reduced by > 75% and had signifcantly lower levels of total P (TP) and Pi contents in leaf and root tissues. Expression dynamics of 12 PHT1 family (PHT1;1–1;12) transporters genes were analyzed in 7 millets. PHT1;2 has been found to be a constitutive transporter gene in all millets. Under LPC, root tissues showed the overexpression of PHT1;2, 1;3, 1;4 and 1;9 in FoxM, PHT1;1, 1;2, 1;3, 1;4, 1;8 and 1;10 in PeaM, PHT1;2 and 1;3 in FinM and ProM and PHT1;3, 1;6 and 1;11 in BarM. In leaf, LPC induced the expression of PHT1;3, 1;4 and 1;6 in FoxM, PHT1;2, 1;3, 1;4 and 1;8 in PeaM, PHT1;2, 1;3 and 1;4 in FinM and KodM, PHT1;2 in LitM and PHT1;4 in ProM and BarnM. This comprehen- sive study on the infuence of P in phenotype, physiology, and molecular responses may help to improve the P uptake and its use efciency of millets in future. Keywords Gene expression · Millets · Phenotyping · Phosphorous · Phosphate transporter 1 (PHT1) · Seed yield Abbreviations BarM Barnyard millet FinM Finger millet FoxM Foxtail millet HPC/LPC High/low Pi condition KodM Kodo millet LitM Little millet LRL/LRN Lateral root length/number PeaM Pearl millet PHT1 Phosphate transporter 1 PRL Primary root length ProM Proso millet RDW/SDW Root/shoot dry weight SW Seed weight (yield) TP Total phosphorus Introduction Millets are small-seeded cereals belonging to the Family Poaceae and are the most important food crops in the arid and semi-arid areas of the world. The predominantly culti- vated millets are fnger millet (FinM) [Eleusine coracana (L.) Gaertn.], foxtail millet (FoxM) [Setaria italica (L.)], pearl millet (PeaM) [Cenchrus americanus (L.) Morrone.], Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00425-019-03237-9) contains supplementary material, which is available to authorized users. * Stanislaus Antony Ceasar antonyceasar@loyolacollege.edu; antony_sm2003@yahoo.co.in 1 Division of Plant Biotechnology, Entomology Research Institute, Loyola College, Chennai 600034, India 2 Functional Genomics and Plant Molecular Imaging Lab, University of Liege, 4000 Liege, Belgium