NIGT1 represses plant growth and mitigates phosphate starvation signaling to balance the growth response tradeoff in rice

Inorganic phosphate(Pi)availability is an important factor which affects the growth and yield of crops,thus an appropriate and effective response to Pi fluctuation is critical.However,how crops orchestrate Pi signaling and growth under Pi starvation conditions to optimize the growth defense tradeoff remains unclear.Here we show that a Pi starvationinduced transcription factor NIGT1(NITRATE-INDUCIBLE GARP-TYPE TRANSCRIPTIONAL REPRESSOR 1)controls plant growth and prevents a hyper-response to Pi starvation by directly repressing the expression of growth-related and Pisignaling genes to achieve a balance between growth and response under a varying Pi environment.NIGT1 directly binds to the promoters of Pi starvation signaling marker genes,like IPS1,mi R827,and SPX2,under Pi-deficient conditions to mitigate the Pi-starvation responsive(PSR).It also directly represses the expression of vacuolar Pi efflux transporter genes VPE1/2 to regulate plant Pi homeostasis.We further demonstrate that NIGT1 constrains shoot growth by repressing the expression of growth-related regulatory genes,including brassinolide signal transduction master regulator BZR1,cell division regulator CYCB1;1,and DNA replication regulator PSF3.Our findings reveal the function of NIGT1 in orchestrating plant growth and Pi starvation signaling,and also provide evidence that NIGT1 acts as a safeguard to avoid hyper-response during Pi starvation stress in rice.

High transcriptome plasticity drives phosphate starvation responses in tomato

Tomato is an important vegetable crop and fluctuating available soil phosphate(Pi)level elicits several morpho-physiological responses driven by underlying molecular responses.Therefore,understanding these molecular responses at the gene and isoform levels has become critical in the quest for developing crops with improved Pi use efficiency.A quantitative time-series RNA-seq analysis was performed to decipher the global transcriptomic changes that accompany Pi starvation in tomato.Apart from changes in the expression levels of genes,there were also alterations in the expression of alternatively-spliced transcripts.Physiological responses such as anthocyanin accumulation,reactive oxygen species generation and cell death are obvious 7 days after Pi deprivation accompanied with the maximum amount of transcriptional change in the genome making it an important stage for in-depth study while studying Pi stress responses(PSR).Our study demonstrates that transcriptomic changes under Pi deficiency are dynamic and complex in tomato.Overall,our study dwells on the dynamism of the transcriptome in eliciting a response to adapt to low Pi stress and lays it bare.Findings from this study will prove to be an invaluable resource for researchers using tomato as a model for understanding nutrient deficiency.