Mikhail Nasrallah

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Mikhail Elia Nasrallah is a plant scientist, specialising in the genetics of self-incompatibility in flowering plants. He is professor emeritus in the Plant Biology Section of the School of Integrative Plant Science in the New York State College of Agriculture and Life Sciences at Cornell University. [1]

Contents

Education

Nasrallah was born in Kfarmishki, Lebanon. He received a Bachelor of Science degree in Agriculture and a certification in Agronomy [Ingénieur Agricole] from the American University of Beirut in 1960, a Master's degree in Horticulture from the University of Vermont in 1962, [2] and a doctorate degree in Plant Breeding and Genetics from Cornell University in 1965. [3]

Career and Research

Nasrallah carried out postdoctoral research at Cornell University from 1965-1967. He had a faculty position in Genetics at the State University of New York/Cortland from 1967 to 1985,[ citation needed ] and subsequently moved to Cornell University.

Much of Nasrallah's research has focused on the molecular genetic analysis of self-incompatibility in plants of the crucifer (Brassicaceae) family. Self-incompatibility prevents flowering plants from self-fertilizing or reproducing with genetically-related plants. [4]

Over the course of his career, Nasrallah's work has resulted in numerous scientific publications which have been cited over 10,000 times with an h-index of 51. [5] His research has also been featured in several perspective articles and paper alerts in high-impact journals. [6] [7] [8]

As a doctoral student at Cornell, Nasrallah made a major scientific contribution by devising a new approach to the molecular analysis of self-incompatibility. Instead of the pollen-centric focus which at the time had been the norm in research aimed at identifying the molecular components of self-incompatibility in various plant families, [9] he reasoned that investigating the contribution of the pistil to the self-incompatibility response would be a more successful approach for identifying molecules involved in SI. Working in Brassica , he focused on the stigma, which is the structure that caps the pistil and at the surface of which "self" pollen grains are inhibited in self-incompatible crucifers. This approach led him to identify the first molecule encoded by an self-incompatibility–determining gene. [10] This strategy of using the pistil as a starting point for identifying the molecular components of self-incompatibility has become common practice for molecular analysis of self-incompatibility across various plant families. [11]

The stigma molecule identified by Nasrallah was later used by his team at Cornell as a launching pad for a detailed analysis of the S locus, whose large number of variants (classically known as "alleles") control recognition of "self" pollen in self-incompatible Brassica plants. This analysis led to the breakthrough demonstration that the S locus is a complex locus and that its "alleles" are in fact haplotypes, each of which contains two genes that encode, respectively, the stigma and pollen determinants of self-incompatibility: a receptor protein kinase displayed at the surface of the stigma epidermal cells that capture pollen [12] and its small protein ligand located in the outer coating of pollen grains. [13] His team conducted gene transfer experiments that demonstrated that these two genes are necessary and sufficient for determining specificity in the self-incompatibility response. [14] [15] The subsequent finding that the interaction of the stigma receptor with its pollen ligand, and hence receptor activation, is S haplotype-specific (i.e. they will only occur if the pollen ligand and the stigma receptor are derived from the same S haplotype) explained how the stigma can discriminate between self- and non-self pollen grains in self-incompatible crucifers. [16] [17] This mechanism of self-recognition has now been shown to operate in all tested self-incompatible species from various crucifer genera, such as Brassica, Arabidopsis , and Capsella.

Awards and Honors

Nasrallah received the American University of Beirut's highest scholastic honor, the Penrose Award, in 1960; [18] an award in Horticulture from the Burpee Foundation [19] in 1961; and an award from the American Institute of Biological Sciences [20] in 1970 in recognition of an outstanding research contribution related to a vegetable crop used for processing.

Related Research Articles

<i>Arabidopsis thaliana</i> Model plant species in the family Brassicaceae

Arabidopsis thaliana, the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally considered a weed.

<span class="mw-page-title-main">Fertilisation</span> Union of gametes of opposite sexes during the process of sexual reproduction to form a zygote

Fertilisation or fertilization, also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a zygote and initiate its development into a new individual organism or offspring. While processes such as insemination or pollination, which happen before the fusion of gametes, are also sometimes informally referred to as fertilisation, these are technically separate processes. The cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms, the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation.

<span class="mw-page-title-main">Pollen tube</span> Tubular structure to conduct male gametes of plants to the female gametes

A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. In maize, this single cell can grow longer than 12 inches (30 cm) to traverse the length of the pistil.

<span class="mw-page-title-main">Self-pollination</span> Form of pollination

Self-pollination is a form of pollination in which pollen arrives at the stigma of a flower or at the ovule of the same plant. The term cross-pollination is used for the opposite case, where pollen from one plant moves to a different plant.

Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals (dioecy), and their various modes of spatial (herkogamy) and temporal (dichogamy) separation.

<i>Brassica oleracea</i> Species of plant

Brassica oleracea is a plant species from family Brassicaceae that includes many common cultivars used as vegetables, such as cabbage, broccoli, cauliflower, kale, Brussels sprouts, collard greens, Savoy cabbage, kohlrabi, and gai lan.

<i>Raphanus raphanistrum</i> Species of flowering plant

Raphanus raphanistrum, also known as wild radish, white charlock or jointed charlock, is a flowering plant in the family Brassicaceae. The species is native to western Asia, Europe and parts of Northern Africa. It has been introduced into most parts of the world and is regarded as a habitat threatening invasive species in many areas, for example, Australia. It spreads rapidly and is often found growing on roadsides or in other places where the ground has been disturbed. The cultivated radish, widely used as a root vegetable, is sometimes considered to be one of its subspecies as Raphanus raphanistrum subsp. sativus.

<span class="mw-page-title-main">Double fertilization</span> Complex fertilization mechanism of flowering plants

Double fertilization or double fertilisation is a complex fertilization mechanism of angiosperms. This process involves the fusion of a female gametophyte or megagametophyte, also called the embryonic sac, with two male gametes (sperm). It begins when a pollen grain adheres to the stigmatic surface of the carpel, the female reproductive structure of angiosperm flowers. The pollen grain begins to germinate, forming a pollen tube that penetrates and extends down through the style toward the ovary as it follows chemical signals released by the egg. The tip of the pollen tube then enters the ovary by penetrating through the micropyle opening in the ovule, and releases two sperm into the embryonic sac (megagametophyte).

In biology, cell signaling is the process by which a cell interacts with itself, other cells, and the environment. Cell signaling is a fundamental property of all cellular life in prokaryotes and eukaryotes.

The mechanisms of reproductive isolation are a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation. They prevent members of different species from producing offspring, or ensure that any offspring are sterile. These barriers maintain the integrity of a species by reducing gene flow between related species.

<span class="mw-page-title-main">TEK tyrosine kinase</span> Protein-coding gene in the species Homo sapiens

Angiopoietin-1 receptor also known as CD202B is a protein that in humans is encoded by the TEK gene. Also known as TIE2, it is an angiopoietin receptor.

<span class="mw-page-title-main">GPR55</span> Protein-coding gene in the species Homo sapiens

G protein-coupled receptor 55 also known as GPR55 is a G protein-coupled receptor that in humans is encoded by the GPR55 gene.

<span class="mw-page-title-main">GFRA3</span> Protein-coding gene in the species Homo sapiens

GDNF family receptor alpha-3 (GFRα3), also known as the artemin receptor, is a protein that in humans is encoded by the GFRA3 gene.

<span class="mw-page-title-main">Gynodioecy</span> Coexistence of female and hermaphrodite within a population

Gynodioecy is a rare breeding system that is found in certain flowering plant species in which female and hermaphroditic plants coexist within a population. Gynodioecy is the evolutionary intermediate between hermaphroditism and dioecy.

Peptide signaling plays a significant role in various aspects of plant growth and development and specific receptors for various peptides have been identified as being membrane-localized receptor kinases, the largest family of receptor-like molecules in plants. Signaling peptides include members of the following protein families.

<span class="mw-page-title-main">Monocotyledon reproduction</span> Flowering plant reproduction system

The monocots are one of the two major groups of flowering plants, the other being the dicots. In order to reproduce they utilize various strategies such as employing forms of asexual reproduction, restricting which individuals they are sexually compatible with, or influencing how they are pollinated. Nearly all reproductive strategies that evolved in the dicots have independently evolved in monocots as well. Despite these similarities and their close relatedness, monocots and dicots have distinct traits in their reproductive biologies.

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Christian Dumas is a French biologist born on January 2, 1943. He is a professor at the École normale supérieure (ENS) in Lyon. Dumas has devoted himself to the study of the specific sexual reproduction mechanisms of flowering plants and their applications for the genetic improvement of cultivated plants. He is also the scientific director of the botanical garden of the Parc de la Tête d'Or in Lyon.

<span class="mw-page-title-main">Distyly</span>

Distyly is a type of heterostyly in which a plant demonstrates reciprocal herkogamy. This breeding system is characterized by two separate flower morphs, where individual plants produce flowers that either have long styles and short stamens, or that have short styles and long stamens. However, distyly can refer to any plant that shows some degree of self-incompatibility and has two morphs if at least one of the following characteristics is true; there is a difference in style length, filament length, pollen size or shape, or the surface of the stigma. Specifically these plants exhibit intra-morph self-incompatibility, flowers of the same style morph are incompatible. Distylous species that do not exhibit true self-incompatibility generally show a bias towards inter-morph crosses - meaning they exhibit higher success rates when reproducing with an individual of the opposite morph.

June Nasrallah is Barbara McClintock Professor in the Plant Biology Section of the School of Integrative Plant Science at Cornell University. Her research focuses on plant reproductive biology and the cell-cell interactions that underlie self-incompatibility in plants belonging to the mustard (Brassicaceae) family. She was elected to the US National Academy of Sciences in 2003 for this work and her contributions generally to our understanding of receptor-based signaling in plants.

References

  1. ↑ "Mikhail Nasrallah | CALS" . Retrieved 2024-07-26.
  2. ↑ Nasrallah, Mikhail (1962). MS thesis: Hybridization and inheritance studies in Solanum melongena L., and selected Solanum species. University of Vermont Howe Library. Retrieved 28 June 2024.
  3. ↑ Nasrallah, Mikhail (1965). Physiological and immunogenetic studies on self-incompatibility in Brassica oleracea var. capitata (Ph. D. thesis). Ithaca, NY: Cornell University. Retrieved 28 June 2024.
  4. ↑ Charlesworth, D (2010). "Self-Incompatibility". F1000 Biol. Rep. 2: 68. doi: 10.3410/B2-68 . PMC   2989624 . PMID   21173841.
  5. ↑ "Mikhail E. Nasrallah". scholar.google.com. Retrieved June 28, 2024.
  6. ↑ Charlesworth, D (2000). "Plant Genetics: Unlocking the secrets of self-incompatibility". Current Biology. 10 (5): R184-R186. Bibcode:2000CBio...10.R184C. doi:10.1016/s0960-9822(00)00347-x. PMID   10712893.
  7. ↑ Franklin-Tong, VE; Franklin, FCH (2000). "Self-incompatibility in Brassica: The elusive pollen S gene is identified!". Plant Cell. 12 (3): 305-308. doi:10.1105/tpc.12.3.305. PMC   1464689 . PMID   10715315.
  8. ↑ Schneiz, K (2002). "Plant Biology Paper alert". Current Opinion in Plant Biology. 5: 467. doi:10.1016/S1369-5266(02)00308-4.
  9. ↑ Lewis, D (1952). "Serological reactions of pollen incompatibility substances". Proceedings of the Royal Society of London. Series B - Biological Sciences. 140 (898): 127–135. Bibcode:1952RSPSB.140..127L. doi:10.1098/rspb.1952.0049. PMID   13003917. S2CID   7071084.
  10. ↑ Nasrallah, ME; Wallace, DH (1967). "Immunochemical detection of antigens in self-incompatibility genotypes of cabbage". Nature. 213 (5077): 700–701. Bibcode:1967Natur.213..700N. doi:10.1038/213700a0. S2CID   4174539.
  11. ↑ Franklin-Tong, VE (2008). Self-incompatibility in Flowering Plants: Evolution, Diversity, and Mechanisms (eBook ed.). Berlin, Heidelberg: Springer-Verlag. ISBN   9783540684862.
  12. ↑ Stein, JC; Howlett, B; Boyes, DC; Nasrallah, ME; Nasrallah, JB (1991). "Molecular cloning of a putative receptor protein kinase gene encoded at the self-incompatibility locus of Brassica oleracea". Proceedings of the National Academy of Sciences USA. 88 (19): 8816–8820. Bibcode:1991PNAS...88.8816S. doi: 10.1073/pnas.88.19.8816 . PMC   52601 . PMID   1681543.
  13. ↑ Schopfer, CR; Nasrallah, ME; Nasrallah, JB (1999). "The male determinant of self-incompatibility in Brassica". Science. 286 (5445): 1697–1700. doi:10.1126/science.286.5445.1697. PMID   10576728.
  14. ↑ Schopfer, CR; Nasrallah, ME; Nasrallah, JB (1999). "The male determinant of self-incompatibility in Brassica". Science. 286 (5445): 1697–1700. doi:10.1126/science.286.5445.1697. PMID   10576728.
  15. ↑ Nasrallah, ME; Liu, P; Nasrallah, JB (2002). "Generation of self-incompatible Arabidopsis thaliana by transfer of two S locus genes from A. lyrata". Science. 297 (5579): 247–249. Bibcode:2002Sci...297..247N. doi:10.1126/science.1072205. PMID   2114625.
  16. ↑ Kachroo, A; Schopfer, CR; Nasrallah, ME; Nasrallah, JB (2001). "Allele-specific receptor-ligand interactions in Brassica self-incompatibility". Science. 293 (5536): 1824–1826. Bibcode:2001Sci...293.1824K. doi:10.1126/science.1062509. PMID   11546871.
  17. ↑ Takayama, S; Shimosato, H; Shiba, H; Funato, M; Che, FS; Watanabe, M; Iwano, M; Isogai, A (2001). "Direct ligand-receptor complex interaction controls Brassica self-incompatibility". Nature. 413 (6855): 534–538. Bibcode:2001Natur.413..534T. doi:10.1038/35097104. PMID   11586363.
  18. ↑ "Maingate/Then and Now" (PDF). No. Summer 2009. American University of Beirut. 2009.
  19. ↑ "The Burpee Foundation". The Burpee Foundation.
  20. ↑ "AIBS Awards". aibs.org.
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