Wastewater leakage in West Texas revealed by satellite radar imagery and numerical modeling

InSAR-observed surface deformation in New Mexico's Permian Basin shows threats and opportunities presented by leaky injection wells

Knowledge of aquifer dynamics, including groundwater storage changes, is key to effective groundwater resource and reservoir management. Resolving and accurate modeling of these processes requires knowledge of subsurface poroelastic properties and lateral heterogeneity within units of interest. Computationally demanding methods for determining lateral heterogeneity in poroelastic properties exist but remain difficult to practically employ. The InSAR-based detection of uplift over a New Mexico well with a casing breach provides an opportunity to determine poroelastic properties using a tractable 2D analytical plane strain solution for surface uplift created by a pressurized reservoir with overburden. Using a Bayesian inversion framework, we calculate poroelastic properties under deep (depth of well-screen) and shallow (depth of well-breach) conditions. We find that shallow injection is necessary to produce the observed deformation. However, pressure-varying forward solutions for uplift are required to reproduce the temporal evolution of deformation. For this we use realistic shallow poroelastic properties and well dynamics, which reflect the evolving injection conditions at the well breach as the casing further erodes. Analysis of individual interferograms or InSAR time series may provide insights into shallow subsurface heterogeneity or anomalous injection conditions at operating wells more rapidly than scheduled field inspections.

A mutation in the promoter of the arabinogalactan protein 7-like gene PcAGP7-1 affects cell morphogenesis and brassinolide content in pear (Pyrus communis L.) stems

Dwarfing rootstocks and dwarf cultivars are urgently needed for modern pear cultivation. However, germplasm resources for dwarfing pear are limited, and the underlying mechanisms remain unclear. We previously showed that dwarfism in pear is controlled by the single dominant gene PcDw (Dwarf). We report here that the expression of PcAGP7-1 (ARABINOGALACTAN PROTEIN 7-1), a key candidate gene for PcDw, is significantly higher in dwarf-type pear plants because of a mutation in an E-box in the promoter. Electrophoretic mobility shift assays and transient infiltration showed that the transcription factors PcBZR1 and PcBZR2 could directly bind to the E-box of the PcAGP7-1 promoter and repress transcription. Moreover, transgenic pear lines overexpressing PcAGP7-1 exhibited obvious dwarf phenotypes, whereas RNA interference pear lines for PcAGP7-1 were taller than controls. PcAGP7-1 overexpression also enhanced cell wall thickness, affected cell morphogenesis, and reduced brassinolide (BL) content, which inhibited BR signaling via a negative feedback loop, resulting in further dwarfing. Overall, we identified a dwarfing mechanism in perennial woody plants involving the BL-BZR/BES-AGP-BL regulatory module. Our findings provide insight into the molecular mechanism of plant dwarfism and suggest strategies for the molecular breeding of dwarf pear cultivars.

Functional characterization of late embryogenesis abundant genes and promoters in pearl millet (Pennisetum glaucum L.) for abiotic stress tolerance

Late embryogenesis abundant (LEA) genes display distinct functions in response to abiotic stresses in plants. In pearl millet (Pennisetum glaucum L.), a total of 21 PgLEA genes were identified and classified into six groups including LEA1, LEA2, LEA3, LEA5, LEA7, and dehydrins (DHN). Open reading frames (ORFs) of PgLEAs range from 291 bp (PgLEA1-1) to 945 bp (PgLEA2-11) and distributed randomly among the seven chromosomes. Phylogenetic analysis revealed that all PgLEA proteins are closely related to sorghum LEA proteins. The PgLEAs were found to be expressed differentially under high progressive vapor pressure deficit (VPD), PgLEA7 was significantly expressed under high VPD and was selected for functional validation. In silico analysis of the PgLEA promoter regions revealed abiotic stress-specific cis-acting elements such as ABRE, CCAAT, MYBS, and LTRE. Based on the type of motifs, PgLEAPC promoter (758 bp), its deletion 1 (PgLpd1, 349 bp) and deletion 2 (PgLpd2, 125 bp) were cloned into the plant expression vector pMDC164 having the promoter-less uidA gene. All the three plant expression vectors were introduced into tobacco through Agrobacterium tumefaciens-mediated transformation to obtain T₁ and T₂ generations of transgenic plants. Based on expression of the uidA gene, tissue-specific expression was observed in mature stems, roots and seedlings of PgLEAPC and PgLpd1 carrying transgenics only. While the transgenic PgLEAPC plants displayed significantly higher uidA expression in the stem and root tissues under salt, drought, heat, and cold stresses, very low or no expression was observed in PgLpd1 and PgLpd2 transgenics under the tested stress conditions. The results of this study indicate that the complete promoter of PgLEAPC plays a role in developing abiotic stress tolerance in plants.

Taking the pulse of aging oil wells in the Permian Basin from space

Thousands of unplugged abandoned oil wells throughout the Permian Basin - one of world's leading oil plays - have potential to create ground instability and damage the environment due to aging facilities and instances of mismanagement. Satellite radar remote sensing technologies, capable of detecting subtle surface changes over time with broad geographic coverage, are a valuable tool for monitoring the health and integrity of aging oil wells by gauging the stability of the well and its surroundings.