Monsanto (India)

Abstract. Cotton cultivation has made rapid strides in India since the introduction of Bt cotton, which provided effective protection against its major pest, Helicoverpa armigera and other bollworms. The presence of alternate host crops for cotton bollworms targeted by Bt cotton play a key role in resistance evolution to the in planta expressed Bt proteins. Several host crops for H. armigera such as pigeonpea, sorghum, tomato, chilli, sunflower and corn are cultivated alongside Bt cotton. Change detection in the extent of cotton and alternate host crops of cotton bollworm was conducted using IRS LISS-III data in Punjab, Haryana, Rajasthan, Gujarat, Maharashtra, Andhra Pradesh and Karnataka states. The changes in the extent of cotton and host crops were monitored using multi-temporal data of 2002, 2004 and 2008. The results indicated that Bt cotton (Hirsutum) has almost completely replaced the traditional Indian cotton (Gossypium arborium). Several alternate host crops of H. armigera were grown along with cotton. Pigeonpea was the major host crop in almost all the locations. Chilies dominated in Andhra Pradesh, sunflower in Karnataka and corn in Gujarat. These host crops serve as ‘natural’ refuge of H. armigera and possibly, for this reason this pest has not evolved resistance to the Bt expressed by Bollgard II even after 16 seasons of intensive cultivation; whereas the pink bollworm, a monophagous cotton bollworm, had developed resistance to Cry1Ac in 2009 and to Cry1Ac and Cry2Ab in 2015.

Bollgard-II cotton expressing Cry1Ac and Cry2Ab2 insecticidal proteins has been commercially cultivated in India since 2006 to control bollworms. These genes were introgressed into parental germplasm of numerous hybrids. Therefore, it is imperative that these insecticidal proteins are expressed in sufficient quantities in different tissues, throughout the season irrespective of genetic background or environmental conditions for effective performance. Here, we document results of a comprehensive study on pattern of expression of Bt proteins across different stages of crop growth in > 2000 cotton hybrids (Gossypium hirsutum), across 12 cropping seasons tested in the Northern, Southern or Central zones in India, in terminal leaf, pre-candle square and boll epicarp tissues. Statistical analysis of variability using Linear mixed effect model was used to estimate factors contributing to variability in expression of Bt proteins. For Cry1Ac, variability was maximally contributed by genotype×season×plant growth stage effect in terminal leaves and boll epicarp, while season effect drove variability in pre-candle square. In Cry2Ab2, season effect drove variability in three tissue types. Pre-candle square tissue had most variability in expression of both proteins followed by terminal leaf and boll epicarp. Further, expression of Bt proteins in 234 G. hirsutum×G. barbadense hybrids showed similar expression patterns as intra specific hybrids though there was a significant difference in expression levels. Cry2Ab2 was expressed in significantly higher amounts when genes were in homozygous state. Bt proteins were also found to be expressed in varied amounts in different tissues and were expressed even when hybrids were grown at sub-optimal temperatures.

Arabidopsis root with its simple, consistent and well-defined pattern of cell division and growth is a highly tractable system for studying cellular development. The root apical meristem (RAM) of Arabidopsis, established post-embryonically is the main source of root cells. Complex bidirectional signaling between stem cells and mature root cells is required to maintain RAM activity. The Arabidopsis RAM comprises of a quiescent center (QC) and a niche of self-renewing stem cells that perform asymmetric (formative) cell divisions to generate daughter cells. These daughter cells subsequently divide symmetrically within delineated longitudinal cell files. The cells in the QC coordinate with neighboring stem cells to establish the balance between proliferation and differentiation in the meristem niche. The Arabidopsis primary root is composed of concentric rings of tissues (namely, the epidermis, the cortex, the endodermis and the pericycle, from the outside inwards) arranged in a radial axis that surrounds a central cylinder of vascular and procambial cells. Overlaid upon the radial organization of the root are three longitudinal zones viz, the meristem, the elongation zone and the differentiation zone, that describe cellular behavior. The boundaries of these domains are plastic and are largely regulated by antagonistic interactions between different phyto-hormones, which regulate the expression of key TFs. In this paper, we review the process of radial patterning in Arabidopsis thaliana post-embryonic root with an emphasis on genetic and molecular networks that determine the fate of each domain in the root.

Leaf rust of barley is caused by the macrocyclic, heteroecious rust pathogen Puccinia hordei, with aecia reported from selected species of the genera Ornithogalum, Leopoldia, and Dipcadi, and uredinia and telia occurring on Hordeum vulgare, H. vulgare ssp. spontaneum, Hordeum bulbosum, and Hordeum murinum, on which distinct parasitic specialization occurs. Although Puccinia hordei is sporadic in its occurrence, it is probably the most common and widely distributed rust disease of barley. Leaf rust has increased in importance in recent decades in temperate barley-growing regions, presumably because of more intensive agricultural practices. Although total crop loss does not occur, under epidemic conditions yield reductions of up to 62% have been reported in susceptible varieties. Leaf rust is primarily controlled by the use of resistant cultivars, and, to date, 21 seedling resistance genes and two adult plant resistance (APR) genes have been identified. Virulence has been detected for most seedling resistance genes but is unknown for the APR genes Rph20 and Rph23. Other potentially new sources of APR have been reported, and additivity has been described for some of these resistances. Approaches to achieving durable resistance to leaf rust in barley are discussed.

Barley (Hordeum vulgareL.) possesses a large and highly repetitive genome of 5.1 Gb that has hindered the development of a complete sequence. In 2012, the International Barley Sequencing Consortium released a resource integrating whole-genome shotgun sequences with a physical and genetic framework. However, since only 6,278 BACs in the physical map were sequenced, detailed fine structure was limited. To gain access to the gene-containing portion of the barley genome at high resolution, we identified and sequenced 15,622 BACs representing the minimal tiling path of 72,052 physical mapped gene-bearing BACs. This generated about 1.7 Gb of genomic sequence containing 17,386 annotated barley genes. Exploration of the sequenced BACs revealed that although distal ends of chromosomes contain most of the gene-enriched BACs and are characterized by high rates of recombination, there are also gene-dense regions with suppressed recombination. Knowledge of these deviant regions is relevant to trait introgression, genome-wide association studies, genomic selection model development and map-based cloning strategies. Sequences and their gene and SNP annotations can be accessed and exported via http://harvest-web.org/hweb/utilmenu.wc or through the software HarvEST:Barley (download from harvest.ucr.edu). In the latter, we have implemented a synteny viewer between barley andAegilops tauschiito aid in comparative genome analysis.

The use of particle gun for the production of marker-free plants is scant in published literature. Perhaps this is a reflection of the widely held notion that the events generated through bombardment tend to have multiple copies of transgenes, usually integrated at a single locus, features which precludes segregating away the selectable marker gene. However, our previous studies have shown that single-copy integrants are obtained at a high frequency if limited quantity of DNA is used for bombardment. Also, the concatemerized insertion of transgenes has been demonstrated to be greatly reduced if "cassette DNA" is employed in place of whole plasmid DNA for bombardment. Based on the above findings, in the present study the feasibility of co-bombardment was evaluated for the production of marker-free plants in corn, employing a combination of limited quantity DNA and cassette DNA approaches for bombardment. Transgenic events were generated after co-bombardment of a selectable marker cassette containing the nptII gene (2.5 ng per shot) and a GUS gene cassette (15 ng per shot). Among these events single-copy integrants for nptII gene occurred at an average frequency of 68% within which the co-expression frequency of GUS and nptII genes ranged from 41% to 80%. Marker-free corn plants could be identified from the progeny of 28 out of the 103 R0 co-expressing events screened. The results demonstrate that by using cassette DNA and low quantities of DNA for bombardment, marker-free plants are produced at efficiencies comparable to that of Agrobacterium-based co-transformation methods.