Katherine Esau (1898 – 1997)

Katherine Esau was born in Yekaterinoslav, Russian Empire (now Dnipropetrovsk, Ukraine) to a family of

Mennonites of German descent. She learned to read and write at home, before attending school. After finishing Gymnasium in 1916, she entered the Golitsin Women's Agricultural College in Moscow and began her studies in the natural sciences, physics, chemistry, and geology. The Revolution interrupted her schooling after the first year, at the end of two semesters. As travel became impossible, she remained in Yekaterinoslav waiting for further developments. In the meantime, she studied English, took piano lessons, attending a gardening school, and collected plants that she was supposed to present at school in the second year.

By 1917, however, the First World War was underway and her studies were not.  Prior to the German occupation of the Ukraine her father had been removed from his post by the "revolutionary" government and was under constant scrutiny. When the war ended, the Esaus fled to Germany. They rode in a third class wagon with wooden benches, together with German officers, the injured and some other refugees. The journey to Berlin lasted two weeks rather than the usual two days because of obstacles put in their way by the revolutionary governments in the cities through which they passed. The day after the Esaus left Yekaterinoslav, posters appeared in the town proclaiming that the new city "Managers" were looking for her father, whom they characterized as a member of the "counterrevolutionary bourgeoisie" and an "enemy of the country."

In Berlin, Dr. Esau registered in the Berlin Landwirtschaftliche Hochschule (Agricultural College of Berlin). Fortunately, she had the foresight to gather her school documents in Russia and carry them with her to Germany. The spring semester was about to begin, so she had to "change gears" from the Russian to German language. During the second year, Dr. Esau went south and spent two semesters in Hohenheim, near Stuttgart, where she enrolled in various agricultural courses. After 2 more semesters in Berlin and a final examination, she received the title "Landwirtschaftlehrerin." With some additional studies she passed a "Zusatzprufung" in plant breeding given by the famous geneticist Erwin Baur.

From Berlin, Dr. Esau went to a large estate in Northern Germany that housed a model seed breeding station for wheat. She worked there until her family emigrated to the United States in 1922.

Her father talked about buying a farm to apply Dr. Esau's agricultural training, but she persuaded him that it would be wiser for her to find a job in a seed company.

Eventually, she was hired by the Spreckels Sugar Company at Spreckels near Salinas, CA. Her main task was to develop a sugarbeet resistant to the curly-top disease. The name curly-top referred to the curling of leaves on diseased plants, which were also severely stunted. The disease was then already recognized as a virus transmitted by the beet leafhopper. The USDA worked on the disease at Riverside, CA, and had evidence that the susceptibility of the plant to curly-top infection varied and that developing a resistant strain seemed a definite possibility. In 1919, Spreckels were actively engaged in breeding work with sugarbeets and succeeded in obtaining a resistant strain, which they named P19, meaning Parent selected in 1919. The strain had a poorly-shaped root and a low sugar content, however. Dr. Esau's task was to improve the P19 strain by hybridization and to make new selections in severely infected fields. The work would be entirely her responsibility.

Despite crude working conditions at Spreckels, genuine progress was being made on the curly-top project. During this time, Dr. Esau began thinking about going back to school. The logical plan seemed for her to do graduate work at Davis and there to continue research with the sugarbeet. An unexpected visitation to Spreckels furthered her plans. The chairman of the Botany Division at Davis, Dr. W. W. Robbins, and the chairman of the Truck Crops Division, Dr. H. A. Jones, came to see what was being done with the sugarbeet and the curly-top problem. Dr. Esau showed them the various plots in the Salinas Valley and, toward the end of the visit, inquired about the chances of doing graduate work at Davis. Dr. Robbins immediately offered to appoint her as an assistant in his division and had no objection to having her work on a project based on the sugarbeet. Spreckels had no objection to her plans, either. In fact, they were pleased that she would continue research on sugarbeets at the University. So, when she left Spreckels in the fall of 1927, a truckload of beets and beet seed followed her car.

In the spring of 1928, Dr. Esau registered as a graduate student. Obstacles in her original research projects inspired some "hard" thinking and she went to Dr. Robbins and explained to him that the Davis campus was not suitable for her original project and proposed to replace it with a study on the effect of the curly-top virus upon the plant. Her research area would now be plant anatomy or, more specifically, pathological anatomy. She had experimental plants, ample space in a greenhouse, colonies of leafhoppers, and the experience on how to handle the insects and how to produce, infected plants, techniques she used many times in subsequent studies.

She was awarded her Ph.D. in December, 1931 and the formal granting of the degree occurred at the Berkeley Commencement of 1932. Upon graduation, Dr. Esau accepted the position of instructor at the Experiment Station of the College of Agriculture. She became a full professor in 1949.

During her career she became increasingly interested in phloem tissue because of the close relation between it and the spread of the disease-induced tissue degeneration. In the early 1960s, Dr. Esau turned to electron microscopy, which greatly enhanced the understanding of virus-plant host relations. As to the phloem itself, electron microscopy began to reveal the role of the unique features of the sieve element in the function of that cell as a conduit of food. Together, these two aspects of phloem research came to dominate her interest in plant science.

Almost all of Dr. Esau's studies involved crop plants. Among those studies, her work on the ontogeny of collenchyma in celery caught the attention of Earle Ennis, who wrote a column called "Smoke Rings" for the San Francisco Chronicle. Apparently, he was amused with the terminology used to describe the celery petiole. Dated Monday, March 1, 1937, the article read as follows:

KATHERINE ESAU, in Hilgardia, a journal of agricultural science, at last has been able to inform a tense world why celery makes a noise when bitten.

Writing under the title, "Ontogeny and Structure of Collenchyma and of Vascular Tissues in Celery Petioles," she explains that "celery petioles have crescent shapes in transverse sections, with prominent ribs on the abaxial side." She asserts further that "A large collenchyma strand, is present in each rib under the epidermis.

Continuing, she says: "Two collenchyma strands occur on the adaxial side, but here two to three subepidermal layers of cells are collenchymatously thickened."

Light began to dawn for us at this point. But Katherine went a bit further and clarified the whole situation. Said she:

"The large vascular bundles are collateral, and the xylem occurs on the adaxial, the phloem on the abaxial side of the bundles."

Well, of course. Naturally. Clear as crystal. We had forgotten all about "xylem." The minute we read that we understood, just as you undoubtedly do, why a celery goes "crunch" when bitten.

In fact, after reading this we bit a stalk of celery and collenchymatously speaking, it acted exactly that way. And we are relieved! It certainly is nice to clear these things up.

In 1960, the Botany Department moved into a proper building named Robbins Hall. At last, her two last

years at Davis, she had a real desk. She was still in the "garage" when she was elected to the National Academy of Sciences in 1957. Dr. Esau moved to Santa Barbara in 1963 to continue her collaborative research on the phloem with Dr. Vernon I. Cheadle, who became Chancellor of the Santa Barbara campus. She worked there until 1992. She was the sixth woman elected to the National Academy of Sciences in 1957, and in 1989, President George Bush awarded Dr. Esau the National Medal of Science.

Esau was a pioneering plant anatomist—perhaps the greatest plant anatomist of the 20th century. Her books Plant Anatomy and Anatomy of Seed Plants have been key plant structural biology texts for four decades.

Dr. Esau was a gifted lecturer and author as well as a brilliant scientist. A kind and modest person, she never married and led a life full of scientific achievements, which inspires female scientists all over the world. The Katherine Esau Award is awarded to the graduate student who presents the best paper in structural and developmental biology at the annual meeting of the Botanical Society of America.

Many of Esau's publications are housed and available for loan from the Cornelius Herman Muller library at the University of California, Santa Barbara's Cheadle Center for Biodiversity and Ecological Restoration.