“ I think I shall never see
A poem lovely as a tree
A tree whose hungry mouth is prest
Against the sweet earth's flowing breast
A tree that looks at God all day
And lifts her leafy arms to pray
A tree that may in summer wear
A nest of robins in her hair
Upon whose bosom snow has lain
Who intimately lives with rain
Poems are made by fools like me
But only God can make a tree. ”
Joyce Kilmer (1886-1918)
It was in March this year that the venerable 800-year-old ginkgo tree of the Kamakura shrine in Japan fell to a snowstorm. Priests and shrine maidens poured consecrated ‘sake' wine on it, added salt and performed purification rites on it. It was this tree that bore witness to the end of the Seiwa Genji shogunate of the Kamakura prefecture on February 12, 1219. On that day, the shogun Sanetomo was coming back from the shrine after celebrating his nomination as the new chief, when his nephew Minamoto attacked and killed him to capture power. For this act, he was beheaded a few hours later, thus ending the shogunate itself.
Trees not only tell history but also inspire awe and spiritualism in people. None is a greater example than Gautama the Buddha, who attained wisdom under the Bodhi tree; hence the name Bodhisatva. A branch of this tree was taken to Sri Lanka in the year 286 BC and planted there at Anuradhapura. This makes it the oldest human-planted tree in the world.
And it was Lord Buddha who said: “A tree is a wonderful living organism which gives food, shelter, warmth and protection to all living things. It even gives shade to those who wield an axe to cut it down”.
And the 81-year-old lady Saalamarada Thimmakka of Hulikal, Ramanagaram District, Karnataka, is a true Buddhist in spirit. When she and her husband realized that they cannot have a baby, she decided to plant trees and parent them as her own children. You can see and listen to her in a TV clip by going to google.com and typing her name and other details.
Trees can be ancient. If the Bodhi tree is about 2,300 years old, the giant sequoia trees of California too are its contemporary. Standing tall at 275 feet high, weighing about 6,000 tons and covering a volume of 1,480 cubic metres (52,500 cubit feet), they are huge.
Even older is the bristlecone pine, aptly named Methusela, standing at 11,000 ft above sea level, it is estimated to be about 48,838 years old. But the oldest tree in the world is reported to be at Dalama in the Norway-Sweden border. It is an evergreen coniferous spruce tree. Scientists estimate that its trunk lives up to 600 years, and that it has cloned itself over the years.
It is this cloning ability that sets plants and trees apart from us animals. It is this that led to the Mahabodhi tree of Anuradhapura, a clone of the one that Lord Buddha sat under, the successors of the Kamakura ginkgo that will come up soon, the Dalama spruce, and the apple tree that Dr Jayant Narlikar has planted at IUCAA, Pune, from a twig of the famous apple tree of England, whose fruit hit Isaac Newton on his head through gravity.
Why do we animals have definite life times, longevities and die as we age? Why can we not clone ourselves into immortality like plants and trees? Even our cells cannot go on dividing and reproducing themselves beyond about 40 cycles. The answer to this puzzle came from an understanding of the mechanism of genetic duplication in our chromosomes.
Each time a chromosome divides and makes a copy of itself, a small bit of its end (called the tail end or telomere) is lost. Thus, after a set number of duplications, the progressive telomere shortening leads to the dead end. Understanding telomere biology and how cells are ‘immortalized' in cancer (through the enzyme called telomerase) came from the work of a large number of people, culminating in the work of Drs. Elizabeth Blackburn and Carol Greider (who won the Nobel in 2009 for this work).
That plants have a somewhat different mechanism of ageing became apparent soon enough, and Dr Barbara McLintock (who won the Nobel for discovering how genes can ‘jump' or transpose themselves) called it ‘chromosome healing'.
We now understand a little better that ageing and telomere action in plants are different from animals. When we talk of an animal's life span, we talk of the survival of its entire body. But in a plant, there is comparatively only a rudimentary body plan. Plants grow in a modular form — individual modules being roots, shoots and branches, leaves, inflorescence and such.
As leaves age and die off, the rest of the plant does not. Also, plants grow using what are called vegetative meristems — these are undifferentiated stem cells that can regenerate into the entire organism. Thus, one can pick up a twig or a branch and grow the entire tree, or graft into another and make a new tree with added features.
And cell death is not the death of the entire organism. A lucid, readable review of the subject is published by Drs. J. Matthew Watson and Karel Riha of Vienna, Austria. Titled “Telomeres, Aging and Plants: From Weeds to Methuselah: A Mini-review”, it is published on line on April 17, 2010 in the journal Gerontology . Those interested may go to google.com, type out the above details and download the entire article free.
