Satish Chandra Maheshwari (1933-2019)-a brilliant, passionate and an outstanding shining light for all of plant biology.

We present here a tribute to Satish Chandra Maheshwari (known to many as SCM, or simply Satish), one of the greatest plant biologists of our time. He was born on October 4, 1933, in Agra, Uttar Pradesh, India, and passed away in Jaipur, Rajasthan, India, on June 12, 2019. He is survived by two of his younger sisters (Sushila Narsimhan and Saubhagya Agrawal), a large number of friends and students from around the world. He has not only been the discoverer of pollen haploids in plants but has also contributed immensely to the field of duckweed research and gene regulation. In addition, he has made discoveries in the area of phytochrome research. The scientific community will always remember him as an extremely dedicated teacher and a passionate researcher; and for his wonderful contributions in the field of Plant Biology. See Sopory and Maheshwari (2001) for a perspective on the beginnings of Plant Molecular Biology in India; and see Raghuram (2002a, b) for the growth and contributions of this field in India.

Oxidative stress induced by destruxin from Metarhizium anisopliae (Metch.) involves changes in glutathione and ascorbate metabolism and instigates ultrastructural changes in the salivary glands of Spodoptera litura (Fab.) larvae.

The cyclodepsipeptidic mycotoxin, destruxin, produced by Metarhizium anisopliae is known for its larvicidal properties. The crude destruxin-treated Spodoptera litura larvae revealed a decrease in thiol content and an increment in oxidation of glutathione to glutathione disulfide and ascorbate to dehydro ascorbate in a dose- and time-dependent manner. An increase in the levels of protein carbonyls and the free radicals, hydrogen peroxide and hydroxyl radical was also observed. These provide a clear indication of oxidative stress. Upon ingestion, destruxin causes serious damage to the epithelial cells of the midgut. We report the ultrastructural effects of crude destruxin on the salivary glands of 9-day-old S. litura larva after 24 h of treatment with the mycotoxin at a dosage of 0.147 microg/g body wt. (LD(50)). The transmission electron microscopic observations revealed characteristic changes in the salivary glands of S. litura which include detachment and damage of the microvilli, epithelial cell vacuolization, bleeding of the epithelial cells into the salivary gland lumen and disruption of the epithelial cell membrane. This investigation focuses salivary glands also as the target organ of destruxin apart from the already known midgut, Malphigian tubules and haemocytes.

Insecticidal activity of destruxin, a mycotoxin from Metarhizium anisopliae (Hypocreales), against Spodoptera litura (Lepidoptera: Noctuidae) larval stages.

BACKGROUND: The cyclodepsipeptide destruxin produced by the entomopathogen Metarhizium anisopliae (Metch.) was administered by different methods, topical application, ingestion and a combination of the two, in an attempt to minimize the mycotoxin dose for efficient management of the insect pest Spodoptera litura (Fab.). RESULTS: The insecticidal activity of destruxin on the larval stages of S. litura showed an ascending trend in LD(50) values with increasing age. The value for 12-day-old larvae in the combined application assay was as low as 0.045 microg g(-1) body weight of crude destruxin from M-19 strain when compared with the corresponding values of 0.17 microg g(-1) body weight in the ingestion assay and 0.237 microg g(-1) body weight in the topical application assay. On the other hand, values were higher in the treatments with crude destruxin from the low-virulence M-10 strain of M. anisopliae showing the least quantities of A and E components of destruxin. CONCLUSION: Laboratory bioevaluation showed the combination assay of ingestion and topical application of crude destruxin to be efficient in enhancing its insecticidal properties. The adopted combination assay apparently simulates application of the insecticide at field level. Quantitative differences between destruxins from low- and high-virulence strains of M. anisopliae are in accordance with its presumed role in virulence.