Discussion on the Relationship Between Senescence Caused by Pi(Spleen)Deficiency and Mitochondrial Autophagy

The Pi(Spleen)is responsible for the formation and transportation,and it is in the center.It is the source of qi and blood generation and transformation,so it has an essential position.If the qi and blood are biochemically passive,the functions of the human body will age prematurely.Mitochondria are for energy synthesis and have always been a hot topic in modern medical research.Many of their functions are similar to those of the Pi in Chinese medicine.In Chinese medicine,strengthening the Pi is to enhance the Pi’s ability to transport and transform,and to speed up the Pi,which is similar to the ability of mitochondria to maintain the ability to remove damaged cells.This can speed up the body’s ability to absorb nutrients and delay aging.

Low phosphorus promotes NSP1–NSP2 heterodimerization to enhance strigolactone biosynthesis and regulate shoot and root architecture in rice

Phosphorus is an essential macronutrient for plant development and metabolism,and plants have evolved ingenious mechanisms to overcome phosphate(Pi)starvation.However,the molecular mechanisms underlying the regulation of shoot and root architecture by low phosphorus conditions and the coordinated utilization of Pi and nitrogen remain largely unclear.Here,we show that Nodulation Signaling Pathway 1(NSP1)and NSP2 regulate rice tiller number by promoting the biosynthesis of strigolactones(SLs),a class of phytohormones with fundamental effects on plant architecture and environmental responses.We found that NSP1 and NSP2 are induced by Oryza sativa PHOSPHATE STARVATION RESPONSE2(OsPHR2)in response to low-Pi stress and form a complex to directly bind the promoters of SL biosynthesis genes,thus markedly increasing SL biosynthesis in rice.Interestingly,the NSP1/2–SL signaling module represses the expression of CROWN ROOTLESS 1(CRL1),a newly identified early SL-responsive gene in roots,to restrain lateral root density under Pi deficiency.We also demonstrated that GR24^(4DO) treatment under normal conditions inhibits the expression of OsNRTs and OsAMTs to suppress nitrogen absorption but enhances the expression of OsPTs to promote Pi absorption,thus facilitating the balance between nitrogen and phosphorus uptake in rice.Importantly,we found that NSP1p:NSP1 and NSP2p:NSP2 transgenic plants show improved agronomic traits and grain yield under low-and medium-phosphorus conditions.Taken together,these results revealed a novel regulatory mechanism of SL biosynthesis and signaling in response to Pi starvation,providing genetic resources for improving plant architecture and nutrient-use efficiency in low-Pi environments.

A transcription factor STOP1-centered pathway coordinates ammonium and phosphate acquisition in Arabidopsis

Phosphorus(P)is an indispensable macronutrient required for plant growth and development.Natural phosphate(Pi)reserves are finite,and a better understanding of Pi utilization by crops is therefore vital for worldwide food security.Ammonium has long been known to enhance Pi acquisition efficiency in agriculture;however,the molecular mechanisms coordinating Pi nutrition and ammonium remains unclear.Here,we reveal that ammonium is a novel initiator that stimulates the accumulation of a key regulatory protein,STOP1,in the nuclei of Arabidopsis root cells under Pi deficiency.We show that Pi deficiency promotes ammonium uptake mediated by AMT1 transporters and causes rapid acidification of the root surface.Rhizosphere acidification-triggered STOP1 accumulation activates the excretion of organic acids,which help to solubilize Pi from insoluble iron or calcium phosphates.Ammonium uptake by AMT1 transporters is downregulated by a CIPK23 protein kinase whose expression is directly modulated by STOP1 when ammonium reaches toxic levels.Taken together,we have identified a STOP1-centered regulatory network that links external ammonium with efficient Pi acquisition from insoluble phosphate sources.These findings provide a framework for developing possible strategies to improve crop production by enhancing the utilization of non-bioavailable nutrients in soil.