Experimental implementation of phase triplicator gratings in a spatial light modulator

In this work,we compare different methods for implementing a triplicator,a phase grating that generates three equiintense diffraction orders.The design with optimal efficiency features a continuous phase profile,which cannot be easily reproduced,and is typically affected by quantization.We compare its performance with binary and sinusoidal phase profiles.We also analyze the effect of quantizing the phase levels.Finally,a random approach is adopted to eliminate the additional harmonic orders.In all cases,a liquid-crystal-on-silicon spatial light modulator is employed to experimentally verify and compare the different approaches.

Getting started in mapping-by-sequencing

Next-generation sequencing （NGS） technologies allow the cost-effective sequencing of whole genomes and have expanded the scope of genomics to novel applications, such as the genome-wide characterization of intraspecific polymorphisms and the rapid mapping and identification of point mutations. Next-generation sequencing platforms, such as the Illumina HiSeq2ooo platform, are now commercially available at affordable prices and routinely produce an enormous amount of sequence data, but their wide use is often hindered by a lack of knowledge on how to manipulateand process the information produced. In this review, we focus on the strategies that are available to geneticists who wish to incorporate these novel approaches into their research but who are not familiar with the necessary bioinformatic concepts and computational tools. In particular, we comprehensively summarize case studies where the use of NGS technologies has led to the identification of point mutations, a strategy that has been dubbed ＂mapping-by-sequencing＇, and review examples from plants and other model species such as Caenorhabditis elegans, Saccharomyces cerevisiae, and Drosophila mela- nogaster. As these technologies are becoming cheaper and more powerful, their use is also expanding to allow mutation identification in species with larger genomes, such as many crop plants.

Anchor Root Development: A World within Worlds

Many plant species develop shoot-borne adventitious roots(ARs)with specialized functions that contribute to plant adaptability by enhancing resource capture and stress avoidance.In Arabidopsis,as in many dicots,the postembryonic root system is primarily composed of lateral roots(LRs),which originate from the xylem pole pericycle cells through a process that involves periodic oscillation in gene expression mediated by a β-carotenoidderived signal(Dickinson et al.,2019).Our understanding of the key molecular and signaling events regulating AR initiation has recently been obtained from studies in Arabidopsis,where ARs are formed on etiolated hypocotyls upon transfer to light(Lakehal et al.,2019)or from excised leaf explants(Zhang et al.,2019).Anchor roots(ANRs)are a type of AR that originate immediately below the root-hypocotyl junction in an auxindependent manner and that require a diapocarotenoid-derived signal(anchorene)to emerge(Jia et al.,2019).ANR primordia activation may represent a generic mechanism to compensate for the loss of the growth potential of the primary root(PR),as it is enhanced by mutations affecting PR growth,by whole-root excision or by nitrogen deficiency(Jia et al.,2019).A recent paper by Bai et al.(2020)provides direct evidence that a regulatory module involving the AP2/ERF transcription factor ABSCISIC ACID INSENSITIVE 4(ABI4),the mitogen-activated protein kinases(MAPKs)MPK3 and MPK6,and the phosphatase PP2C12 controls ANR emergence in Arabidopsis.