Large-scale interplant exchange of macromolecules between soybean and dodder under nutrient stresses

Parasitic plants and their hosts communicate through haustorial connections.Nutrient deficiency is a common stress for plants,yet little is known about whether and how host plants and parasites communicate during adaptation to such nutrient stresses.In this study,we used transcriptomics and proteomics to analyze how soybean(Glycine max)and its parasitizing dodder(Cuscuta australis)respond to nitrate and phosphate deficiency(-N and-P).After-N and-P treatment,the soybean and dodder plants exhibited substantial changes of transcriptome and proteome,although soybean plants showed very few transcriptional responses to-P and dodder did not show any transcriptional changes to either-N or-P.Importantly,large-scale interplant transport of mRNAs and proteins was detected.Although the mobile mRNAs only comprised at most 0.2%of the transcriptomes,the foreign mobile proteins could reach 6.8%of the total proteins,suggesting that proteins may be the major forms of interplant communications.Furthermore,the interplant mobility of macromolecules was specifically affected by the nutrient regimes and the transport of these macromolecules was very likely independently regulated.This study provides new insight into the communication between host plants and parasites under stress conditions.

Lipid droplets and mitochondria are anchored during brown adipocyte differentiation

Dear Editor,Brown adipose tissue(BAT)acts as a site of non-shivering thermogenesis in mammals including adult humans(Ned-ergaard and Cannon,2010).Prolonged cold exposure can induce the acquisition of thermogenic function in white adi­pose tissue(WAT)with the cells that have undergone the"browning"process being referred to as beige cells(Wu et al.,2013).Both mainly use mitochondrial p-oxidation of fatty arid(FA)from lipid drnplotc(I He)in maintaining hnHy temperature.The efficiency of hydrophobic FA transport between two organelles in aqueous cytoplasm has been challenged.Understanding the mechanism underlying the interaction between these two organelles is essential for animal physiology as well as for the development of thera­pies to treat metabolic diseases(Benador et al.,2018).

A pair of transporters controls mitochondrial Zn^(2+) levels to maintain mitochondrial homeostasis

Zn^(2+)is required for the activity of many mitochondrial proteins,which regulate mitochondrial dynamics,apoptosis and mitophagy.However,it is not understood how the proper mitochondrial Zn^(2+)level is achieved to maintain mitochondrial homeostasis.Using Caenorhabditis elegans,we reveal here that a pair of mitochondrion-localized transporters controls the mitochondrial level of Zn^(2+).We demonstrate that SLC-30A9/ZnT9 is a mitochondrial Zn^(2+)exporter.Loss of SLC-30A9 leads to mitochondrial Zn^(2+)accumulation,which damages mitochondria,impairs animal development and shortens the life span.We further identify SLC-25A25/SCaMC-2 as an important regulator of mitochondrial Zn^(2+)import.Loss of SLC-25A25 suppresses the abnormal mitochondrial Zn^(2+)accumulation and defective mitochondrial structure and functions caused by loss of SLC-30A9.Moreover,we reveal that the endoplasmic reticulum contains the Zn^(2+)pool from which mitochondrial Zn^(2+)is imported.These findings establish the molecular basis for controlling the correct mitochondrial levels for normal mitochondrial structure and functions.

Roles of small RNAs in crop disease resistance

Small RNAs(sRNAs)are a class of short,non-coding regulatory RNAs that have emerged as critical components of defense regulatory networks across plant kingdoms.Many sRNA-based technologies,such as host-induced gene silencing(HIGS),spray-induced gene silencing(SIGS),virus-induced gene silencing(VIGS),artificial microRNA(amiRNA)and synthetic trans-acting siRNA(syn-tasiRNA)-mediated RNA interference(RNAi),have been developed as disease control strategies in both monocot and dicot plants,particularly in crops.This review aims to highlight our current understanding of the roles of sRNAs including miRNAs,heterochromatic siRNAs(hc-siRNAs),phased,secondary siRNAs(phasiRNAs)and natural antisense siRNAs(nat-siRNAs)in disease resistance,and sRNAs-mediated trade-offs between defense and growth in crops.In particular,we focus on the diverse functions of sRNAs in defense responses to bacterial and fungal pathogens,oomycete and virus in crops.Further,we highlight the application of sRNA-based technologies in protecting crops from pathogens.Further research perspectives are proposed to develop new sRNAs-based efficient strategies to breed non-genetically modified(GMO),diseasetolerant crops for sustainable agriculture.