CRISPR-Cas9/Cpf1 system with its unique gene targeting efficiency, could be an important tool for functional study of early developmental genes through the generation of successful knockout plants. The introduction and utilization of systems biology approaches have identified several genes that are involved in early development of a plant and with such knowledge a robust tool is required for the functional validation of putative candidate genes thus obtained. The development of the CRISPR-Cas9/Cpf1 genome editing system has provided a convenient tool for creating loss of function mutants for genes of interest. The present study utilized CRISPR/Cas9 and CRISPR-Cpf1 technology to knock out an early developmental gene EPFL9 (Epidermal Patterning Factor like-9, a positive regulator of stomatal development in Arabidopsis) orthologue in rice. Germ-line mutants that were generated showed edits that were carried forward into the T2 generation when Cas9-free homozygous mutants were obtained. The homozygous mutant plants showed more than an eightfold reduction in stomatal density on the abaxial leaf surface of the edited rice plants. Potential off-target analysis showed no significant off-target effects. This study also utilized the CRISPR-LbCpf1 (Lachnospiracae bacterium Cpf1) to target the same OsEPFL9 gene to test the activity of this class-2 CRISPR system in rice and found that Cpf1 is also capable of genome editing and edits get transmitted through generations with similar phenotypic changes seen with CRISPR-Cas9. This study demonstrates the application of CRISPR-Cas9/Cpf1 to precisely target genomic locations and develop transgene-free homozygous heritable gene edits and confirms that the loss of function analysis of the candidate genes emerging from different systems biology based approaches, could be performed, and therefore, this system adds value in the validation of gene function studies.

Professional nursing staff should use frailty indicators in a timely fashion to assess the status of frailty in older people and should effectively develop frailty prevention strategies to decrease the risk for hospitalization and to enhance quality of life for older adults.

Objectives In this study we investigated the correlation between depression and frailty in older adults. Additionally, correlations among study designs (prospective vs. cross‐sectional), regions, depression indices, frailty indices, covariance corrections, and sexes were explored to support the analysis. Methods A systematic literature review and meta‐analysis were conducted. A total of 84,351 older adults, all 65 years of age or older, were analyzed. Both authors independently extracted and examined retrieved articles. Searched keywords included “depression” or “depressive”; “frailty” or “frail”; and “older people,” “elderly,” “geriatric,” or “senior.” Articles published between January 2000 and December 2016 were searched. A literature quality assessment was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses Systematic literature searches were conducted on the Embase, PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Library databases, and collected studies were analyzed using a random effects model. Results Fourteen studies on people 65 years of age or older were collected, and a correlation analysis was conducted for depression and frailty. According to the meta‐analysis, the risk for frailty due to depression was nonsignificant among the subgroups for study design (p for heterogeneity = .149), region (p = .429), depression criteria (p = .934), covariate adjustment (p = .702), and frailty criteria (p = .661). Notably, the risk for frailty due to depression was significantly higher in men than in women (pooled odds ratios for men and women: 4.76 and 2.25, respectively; Qbetween χ2 = 9.93, p = .002). Conclusion Older adults with depression are more prone to frailty than are those without depression. Regardless of study design, region, depression index, frailty index, and covariance corrections, no significant differences were observed in the results of studies on depression and frailty in older adults. The only factor that had a significant influence was sex; older men with depression were at a higher risk for frailty than were older women with depression. Clinical Relevance Depression and frailty are pertinent health concerns related to geriatric syndromes. Because older adults with depression have a high risk for frailty, nursing personnel should use a depression index as early as possible to screen for depression and further reduce the occurrence of frailty in older adults. Furthermore, based on the aforementioned differences between the sexes, special attention should be paid to older men with depression to reduce their risk for frailty.

With the aim of understanding the molecular mechanisms underlying somatic embryogenesis (SE) in oil palm, we examined transcriptome changes that occur when embryogenic suspension cells are initiated to develop somatic embryos. Two reciprocal suppression subtractive hybridization (SSH) libraries were constructed from oil palm embryogenic cell suspensions: one in which embryo development was blocked by the presence of the synthetic auxin analogue 2,4-dichlorophenoxyacetic acid (2,4-D: ) in the medium (proliferation library); and another in which cells were stimulated to form embryos by the removal of 2,4-D: from the medium (initiation library). A total of 1867 Expressed Sequence Tags (ESTs) consisting of 1567 potential unigenes were assembled from the two libraries. Functional annotation indicated that 928 of the ESTs correspond to proteins that have either no similarity to sequences in public databases or are of unknown function. Gene Ontology (GO) terms assigned to the two EST populations give clues to the underlying molecular functions, biological processes and cellular components involved in the initiation of embryo development. Macroarrays were used for transcript profiling the ESTs during SE. Hierarchical cluster analysis of differential transcript accumulation revealed 4 distinct profiles containing a total of 192 statistically significant developmentally regulated transcripts. Similarities and differences between the global results obtained with in vitro systems from dicots, monocots and gymnosperms will be discussed.

The glycine decarboxylase complex (GDC) plays a critical role in the photorespiratory C2 cycle of C3 species by recovering carbon following the oxygenation reaction of ribulose-1,5-bisphosphate carboxylase/oxygenase. Loss of GDC from mesophyll cells (MCs) is considered a key early step in the evolution of C4 photosynthesis. To assess the impact of preferentially reducing GDC in rice MCs, we decreased the abundance of OsGDCH (Os10g37180) using an artificial microRNA (amiRNA) driven by a promoter that preferentially drives expression in MCs. GDC H- and P-proteins were undetectable in leaves of gdch lines. Plants exhibited a photorespiratory-deficient phenotype with stunted growth, accelerated leaf senescence, reduced chlorophyll, soluble protein and sugars, and increased glycine accumulation in leaves. Gas exchange measurements indicated an impaired ability to regenerate ribulose 1,5-bisphosphate in photorespiratory conditions. In addition, MCs of gdch lines exhibited a significant reduction in chloroplast area and coverage of the cell wall when grown in air, traits that occur during the later stages of C4 evolution. The presence of these two traits important for C4 photosynthesis and the non-lethal, down-regulation of the photorespiratory C2 cycle positively contribute to efforts to produce a C4 rice prototype.

All grass leaves are strap-shaped with a series of parallel veins running from base to tip, but the distance between each pair of veins, and the cell-types that develop between them, differs depending on whether the plant performs C3 or C4 photosynthesis. As part of a multinational effort to introduce C4 traits into rice to boost crop yield, candidate regulators of C4 leaf anatomy were previously identified through an analysis of maize leaf transcriptomes. Here we tested the potential of 60 of those candidate genes to alter leaf anatomy in rice. In each case, transgenic rice lines were generated in which the maize gene was constitutively expressed. Lines grouped into three phenotypic classes: (1) indistinguishable from wild-type; (2) aberrant shoot and/or root growth indicating possible perturbations to hormone homeostasis; and (3) altered secondary cell wall formation. One of the genes in class 3 defines a novel monocot-specific family. None of the genes were individually sufficient to induce C4-like vein patterning or cell-type differentiation in rice. A better understanding of gene function in C4 plants is now needed to inform more sophisticated engineering attempts to alter leaf anatomy in C3 plants.

Author contributions 31 JMH and WPQ designed the study. BAJ, DME, SW, VT and SKe conducted the bioinformatic and 32 phylogenetic analysis. SKa, ISL, HSL and WPQ produced and verified the transgenic lines. RC and 33 HSL undertook physiological and metabolic analysis. RG and ABC conducted gas exchange 34 analysis on transgenic plants. FD performed the confocal microscopy. SKe and WPQ analysed the 35 data. SKe Abstract 38Convergent trait evolution is a recurrent phenomenon in all domains of the tree of life. While some 39 convergent traits are caused by simple sequence changes, many are associated with extensive 40 changes to the sequence and regulation of large cohorts of genes. It is unknown how organisms 41 traverse this expansive genotype space to assemble such complex convergent phenotypes. C4 42 photosynthesis is a paradigm of large-scale phenotypic convergence. Conceptual and mathematical 43 models propose that C4 photosynthesis evolved from ancestral C3 photosynthesis through sequential 44 adaptive changes. These adaptive changes could have been rapidly assembled if modifications to 45 the activity and abundance of enzymes of the C4 cycle was neutral in C3 plants. This neutrality would 46 enable populations of C3 plants to maintain genotypes with expression levels of C4 enzymes 47 analogous to those in C4 species and thus enable rapid assembly of a functional C4 cycle from 48 naturally occurring genotypes given shared environmental selection. Here we show that there is 49 substantial natural variation in expression of genes encoding C4 cycle enzymes between natural 50 accessions of the C3 plant Arabidopsis thaliana. We further show through targeted transgenic 51 experiments in the C3 crop Oryza sativa, that high expression of the majority of C4 cycle enzymes in 52 rice is neutral with respect to growth, development, biomass and photosynthesis. Thus, substantial 53 variation in the abundance and activity of C4 cycle enzymes is permissible within the limits of 54 operation of C3 photosynthesis and the emergence of component parts of this complex convergent 55 trait can be facilitated by neutral variation. 56

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