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The significance of priming in enhancing abiotic stress tolerance is well‐established in several important crops. Priming positively impacts plant growth and improves stress tolerance at multiple developmental stages, and seed priming is one of the most used methods. Seed priming influences the pre‐germinative metabolism that ensures proper germination, early seedling establishment, enhanced stress tolerance and yield, even under unfavourable environmental conditions. Seed priming involves pre‐exposure of seeds to mild stress, and this pre‐treatment induces specific changes at the physiological and molecular levels. Interestingly, priming can improve the efficiency of the DNA repair mechanism, along with activation of specific signalling proteins and transcription factors for rapid and efficient stress tolerance. Notably, such acquired stress tolerance may be retained for longer duration, namely, later developmental stages or even subsequent generations. Epigenetic and chromatin‐based mechanisms such as DNA methylation, histone modifications, and nucleosome positioning are some of the key molecular changes involved in priming/stress memory. Further, the retention of induced epigenetic changes may influence the priming‐induced trans‐generational stress memory. This review discusses known and plausible seed priming‐induced molecular mechanisms that govern germination and stress memory within and across generations, highlighting their role in regulating the plant response to abiotic stresses. Understanding the molecular mechanism for activation of stress‐responsive genes and the epigenetic changes resulting from seed priming will help to improve the resiliency of the crops for enhanced productivity under extreme environments. [ABSTRACT FROM AUTHOR]

Abstract: Food security and the protection of the environment are urgent issues for global society, particularly with the uncertainties of climate change. Changing climate is predicted to have a wide range of negative impacts on plant physiology metabolism, soil fertility and carbon sequestration, microbial activity and diversity that will limit plant growth and productivity, and ultimately food production. Ensuring global food security and food safety will require an intensive research effort across the food chain, starting with crop production and the nutritional quality of the food products. Much uncertainty remains concerning the resilience of plants, soils, and associated microbes to climate change. Intensive efforts are currently underway to improve crop yields with lower input requirements and enhance the sustainability of yield through improved biotic and abiotic stress tolerance traits. In addition, significant efforts are focused on gaining a better understanding of the root/soil interface and associated microbiomes, as well as enhancing soil properties. [ABSTRACT FROM AUTHOR]

Summary: Plant seed oil‐based liquid transportation fuels (i.e., biodiesel and green diesel) have tremendous potential as environmentally, economically and technologically feasible alternatives to petroleum‐derived fuels. Due to their nutritional and industrial importance, one of the major objectives is to increase the seed yield and oil production of oilseed crops via biotechnological approaches. Camelina sativa, an emerging oilseed crop, has been proposed as an ideal crop for biodiesel and bioproduct applications. Further increase in seed oil yield by increasing the flux of carbon from increased photosynthesis into triacylglycerol (TAG) synthesis will make this crop more profitable. To increase the oil yield, we engineered Camelina by co‐expressing the Arabidopsis thaliana (L.) Heynh. diacylglycerol acyltransferase1 (DGAT1) and a yeast cytosolic glycerol‐3‐phosphate dehydrogenase (GPD1) genes under the control of seed‐specific promoters. Plants co‐expressing DGAT1 and GPD1 exhibited up to 13% higher seed oil content and up to 52% increase in seed mass compared to wild‐type plants. Further, DGAT1‐ and GDP1‐co‐expressing lines showed significantly higher seed and oil yields on a dry weight basis than the wild‐type controls or plants expressing DGAT1 and GPD1 alone. The oil harvest index (g oil per g total dry matter) for DGTA1‐ and GPD1‐co‐expressing lines was almost twofold higher as compared to wild type and the lines expressing DGAT1 and GPD1 alone. Therefore, combining the overexpression of TAG biosynthetic genes, DGAT1 and GPD1, appears to be a positive strategy to achieve a synergistic effect on the flux through the TAG synthesis pathway, and thereby further increase the oil yield. [ABSTRACT FROM AUTHOR]

Abstract: Members of Stress‐Associated Protein (SAP) family in plants have been shown to impart tolerance to multiple abiotic stresses, however, their mode of action in providing tolerance to multiple abiotic stresses is largely unknown. There are 14 SAP genes in Arabidopsis thaliana containing A20, AN1, and Cys2‐His2 zinc finger domains. AtSAP13, a member of the SAP family, carries two AN1 zinc finger domains and an additional Cys2‐His2 domain. AtSAP13 transcripts showed upregulation in response to Cd, ABA, and salt stresses. AtSAP13 overexpression lines showed strong tolerance to toxic metals (AsIII, Cd, and Zn), drought, and salt stress. Further, transgenic lines accumulated significantly higher amounts of Zn, but less As and Cd accumulation in shoots and roots. AtSAP13 promoter–GUS fusion studies showed GUS expression predominantly in the vascular tissue, hydathodes, and the apical meristem and region of root maturation and elongation as well as the root hairs. At the subcellular level, the AtSAP13–eGFP fusion protein was found to localize in both nucleus and cytoplasm. Through yeast one‐hybrid assay, we identified several AP2/EREBP family transcription factors that interacted with the AtSAP13 promoter. AtSAP13 and its homologues will be highly useful for developing climate resilient crops. [ABSTRACT FROM AUTHOR]

This article reports on the localization of Arabidopsis thaliana formins, AtFH4 and AtFH8, to cross-wall of roots, hypocotyl and shoot tissues. Here, findings from the perspective of plant cell polarity, cell wall-cytoskeleton adhesion domains, polar auxin transport, and the emerging status of these cross-walls in that they resemble neuronal and immunological synapses are discussed. This study opens avenues in the understanding of plant-specific formins as the authors report domain-specific enrichment of AtFH4 and AtFH8 at cross-walls of diverse plant organs. This raises the question as to what is specific about these cross-walls.

Strong, tissue-specific and genetically regulated expression systems are essential tools in plant biotechnology. An expression system tool called a ‘repressor-operator gene complex’ (ROC) has diverse applications in plant biotechnology fields including phytoremediation, disease resistance, plant nutrition, food safety, and hybrid seed production. To test this concept, we assembled a root-specific ROC using a strategy that could be used to construct almost any gene expression pattern. When a modified E. coli lac repressor with a nuclear localization signal was expressed from a rubisco small subunit expression vector, S1pt::lacIn, LacIn protein was localized to the nuclei of leaf and stem cells, but not to root cells. A LacIn repressible Arabidopsis actin expression vector A2pot was assembled containing upstream bacterial lacO operator sequences, and it was tested for organ and tissue specificity using β-glucuronidase ( GUS) and mercuric ion reductase ( merA) gene reporters. Strong GUS enzyme expression was restricted to root tissues of A2pot::GUS/S1pt::lacIn ROC plants, while GUS activity was high in all vegetative tissues of plants lacking the repressor. Repression of shoot GUS expression exceeded 99.9% with no evidence of root repression, among a large percentage of doubly transformed plants. Similarly, MerA was strongly expressed in the roots, but not the shoots of A2pot::merA/S1pt::lacIn plants, while MerA levels remained high in both shoots and roots of plants lacking repressor. Plants with MerA expression restricted to roots were approximately as tolerant to ionic mercury as plants constitutively expressing MerA in roots and shoots. The superiority of this ROC over the previously described root-specific tobacco RB7 promoter is demonstrated. [ABSTRACT FROM AUTHOR]

Summary • Cadmium (Cd) is a major environmental pollutant that poses a serious threat to natural ecosystems. However, most initial attempts to engineer phytoremediation of Cd have not succeeded in developing sufficient Cd tolerance for vigorous plant growth. • We found that the bacterial arsenate reductase gene (arsC ) provided Cd(II) resistance to Escherichia coli . When ArsC is overexpressed in tobacco (Nicotiana tabacum ) and Arabidopsis thaliana , both transgenic plant species showed significantly greater Cd tolerance than wild-type controls. • At 50, 75, and 100 µm concentrations of Cd (II), the ArsC expressing transgenic lines grew bigger with broader leaves and longer roots than wild-type controls, which were stunted, turned yellow, flowered early, and often died. At the various Cd(II) concentrations, ArsC transgenic plants attained f. wt 2–3-fold higher than the wild-type plants and had roots significantly longer than wild-type plants. These transgenic plants also contained 30–50% higher Cd concentrations than wild-type plants. • It is likely that the arsC gene directs Cd tolerance via the electrochemical reduction of Cd(II) to Cd(0). [ABSTRACT FROM AUTHOR]