Inositol signaling is believed to play a crucial role in various aspects of plant growth and adaptation. As an important component in biosynthesis and degradation of myo-inositol and its derivatives, inositol phosphatases could hydrolyze the phosphate of the inositol ring, thus affecting inositol signaling. Until now, more than 30 members of inositol phosphatases have been identified in plants, which are classified intofive families, including inositol polyphosphate 5-phosphatases (5PTases), suppressor of actin (SAC) phosphatases, SAL1 phosphatases, inositol monophosphatase (IMP), and phosphatase and tensin homologue deleted on chromosome 10 (PTEN)-related phosphatases. The current knowledge was revised here in relation to their substrates and function in response to abiotic stress. The potential mechanisms were also concluded with the focus on their activities of inositol phosphatases. The general working model might be that inositol phosphatases would degrade the Ins(1,4,5)P₃ or phosphoinositides, subsequently resulting in altering Ca²⁺ release, abscisic acid (ABA) signaling, vesicle trafficking or other cellular processes.

Continuous planting has a negative impact on sugarcane plant growth and reduces global sugarcane crop production, including in China. The response of soil bacteria, fungal, and arbuscular mycorrhizae (AM) fungal communities to continuous sugarcane cultivation has not been thoroughly documented. Using MiSeq sequencing technology, we analyzed soil samples from sugarcane fields with 1, 10, and 30 years of continuous cropping to see how monoculture time affected sugarcane yield, its rhizosphere soil characteristics and microbiota. The results showed that continuous sugarcane planting reduced sugarcane quality and yield. Continuous sugarcane planting for 30 years resulted in soil acidification, as well as C/N, alkali hydrolyzable nitrogen, organic matter, and total sulfur content significantly lower than in newly planted fields. Continuous sugarcane planting affected soil bacterial, fungal, and AM fungal communities, according to PCoA and ANOSIM analysis. Redundancy analysis (RDA) results showed that bacterial, fungal, and AM fungal community composition were strongly associated with soil properties and attributes, e.g., soil AN, OM, and TS were critical environmental factors in transforming the bacterial community. The LEfSe analysis revealed bacterial families (e.g., Gaiellaceae, Pseudomonadaceae, Micromonosporaceae, Nitrosomonadaceae, and Methyloligellaceae) were more prevalent in the newly planted field than in continuously cultivated fields (10 and 30 years), whereas Sphingomonadaceae, Coleofasciculaceae, and Oxyphotobacteria were depleted. Concerning fungal families, the newly planted field was more dominated than the continuously planted field (30 years) with Mrakiaceae and Ceratocystidaceae, whereas Piskurozymaceae, Trimorphomycetaceae, Lachnocladiaceae, and Stigmatodisc were significantly enriched in the continuously planted fields (10 and 30 years). Regarding AMF families, Diversisporaceae was considerably depleted in continuously planted fields (10 and 30 years) compared to the newly planted field. These changes in microbial composition may ultimately lead to a decrease in sugarcane yield and quality in the monoculture system, which provides a theoretical basis for the obstruction mechanism of the continuous sugarcane planting system. However, continuous planting obstacles remain uncertain and further need to be coupled with root exudates, soil metabolomics, proteomics, nematodes, and other exploratory methods.

Background: Soybean (Glycine max) is an important oil provider and ecosystem participant. The protein phosphatase 2C (PP2C) plays important roles in key biological processes. Molecular evolution and functional analysis of the PP2C family in soybean are yet to be reported.Results: The present study identified 134 GmPP2Cs with 10 subfamilies in soybean. Duplication events were prominent in the GmPP2C family, and all duplicated gene pairs were involved in the segmental duplication events. The legume-common duplication event and soybean-specific tetraploid have primarily led to expanding GmPP2C members in soybean. Sub-functionalization was the main evolutionary fate of duplicated GmPP2C members. Meanwhile, massive genes were lost in the GmPP2C family, especially from the F subfamily. Compared with other genes, the evolutionary rates were slower in the GmPP2C family. The PP2C members from the H subfamily resembled their ancestral genes. In addition, some GmPP2Cs were identified as the putative key regulator that could control plant growth and development.Conclusions: A total of 134 GmPP2Cs were identified in soybean, and their expansion, molecular evolution and putative functions were comprehensively analyzed. Our findings provided the detailed information on the evolutionary history of the GmPP2C family, and the candidate genes can be used in soybean breeding.

Inositol polyphosphate 5-phosphatases (5PTases) function in inositol signaling by regulating the catabolism of phosphoinositol derivatives. Previous reports showed that 5PTases play a critical role in plant development and stress responses. In this study, we identified a novel 5PTase gene, Gs5PTase8, from the salt-tolerance locus of chromosome 3 in wild soybean (Glycine soja). Gs5PTase8 is highly up-regulated under salt treatment. It is localized in the nucleus and plasma membrane with a strong signal in the apoplast. Ectopic expression of Gs5PTase8 significantly increased salt tolerance in transgenic BY-2 cells, soybean hairy roots and Arabidopsis, suggesting Gs5PTase8 could increase salt tolerance in plants. The overexpression of Gs5PTase8 significantly enhanced the activities of catalase and ascorbate peroxidase under salt stress. The seeds of Gs5PTase8-transgenic Arabidopsis germinated earlier than the wild type under abscisic acid treatment, indicating Gs5PTase8 would alter ABA sensitivity. Besides, transcriptional analyses showed that the stress-responsive genes, AtRD22, AtRD29A and AtRD29B, were induced with a higher level in the Gs5PTase8-transgenic Arabidopsis plants than in the wild type under salt stress. These results reveal that Gs5PTase8 play a positive role in salt tolerance and might be a candidate gene for improving soybean adaptation to salt stress.

The comprehensive analysis of gene family evolution will elucidate the origin and evolution of gene families. The K+ uptake (KUP) gene family plays important roles in K+ uptake and transport, plant growth and development, and abiotic stress responses. However, the current understanding of the KUP family in cotton is limited. In this study, 51 and 53 KUPs were identified in Gossypium barbadense and Gossypium hirsutum, respectively. These KUPs were divided into five KUP subfamilies, with subfamily 2 containing three groups. Different subfamilies had different member numbers, conserved motifs, gene structures, regulatory elements, and gene expansion and loss rates. A paleohexaploidization event caused the expansion of GhKUP and GbKUP in cotton, and duplication events in G. hirsutum and G. barbadense have happened in a common ancestor of Gossypium. Meanwhile, the KUP members of the two allopolyploid subgenomes of G. hirsutum and G. barbadense exhibited unequal gene proportions, gene structural diversity, uneven chromosomal distributions, asymmetric expansion rates, and biased gene loss rates. In addition, the KUP families of G. hirsutum and G. barbadense displayed evolutionary conservation and divergence. Taken together, these results illustrated the molecular evolution and expansion of the KUP family in allopolyploid cotton species.