Long‐living lotus: germination and soil γ‐irradiation of centuries‐old fruits, and cultivation, growth, and phenotypic abnormalities of offspring

Abstract

Sacred lotus (Nelumbo nucifera) has been cultivated as a crop in Asia for thousands of years. An ∼1300-yr-old lotus fruit, recovered from an originally cultivated but now dry lakebed in northeastern China, is the oldest germinated and directly (14)C-dated fruit known. In 1996, we traveled to the dry lake at Xipaozi Village, China, the source of the old viable fruits. We identified all of the landmarks recorded by botanist Ichiro Ohga some 80 yr ago when he first studied the deposit, but found that the fruits are now rare. We (1) cataloged a total of 60 lotus fruits; (2) germinated four fruits having physical ages of 200-500 yr by (14)C dating; (3) measured the rapid germination of the old fruits and the initially fast growth and short dormancy of their seedlings; (4) recorded abnormal phenotypes in their leaves, stalks, roots, and rhizomes; (5) determined γ-radiation of ∼2.0 mGy/yr in the lotus-bearing beds; and (6) measured stratigraphic sequences of the lakebed strata. The total γ-irradiation of the old fruits of 0.1-3 Gy (gray, the unit of absorbed dosage defined as 1 joule/kg; 1 Gy = 100 rad), evidently resulting in certain of the abnormal phenotypes noted in their seedlings, represents the longest natural radiobiology experiment yet recorded. Most of the lotus abnormalities resemble those of chronically irradiated plants exposed to much higher irradiances. Though the chronic exposure of the old fruits to low-dose γ-radiation may be responsible in part for the notably weak growth and mutant phenotypes of the seedlings, it has not affected seed viability. All seeds presumably repair cellular damage before germination. Understanding of repair mechanisms in the old lotus seeds may provide insight to the aging process applicable also to other organisms.

Regeneration of whole fertile plants from 30,000-y-old fruit tissue buried in Siberian permafrost

“…Thus, it is reasonable to expect that higher plant tissues, especially those associated with reproductive processes, can be expected to survive better within the permafrost sediments than in any other known habitat. It is also possible that low doses of radiation also might have an effect on the viability of biological objects (13,32).…”

“…At the moment, the oldest viable seeds with the ability to germinate were radiocarbon dated to the first and eighth centuries of the Common Era. These are, respectively, Phoenix dactylifera found near the Dead Sea (12) and Nelumbo nucifera found in northeastern China (13).…”

Proteomic and functional analyses of Nelumbo nucifera annexins involved in seed thermotolerance and germination vigor

“…seed is one of the oldest directly dated seeds that remain viable after hundreds of years (Shen-Miller et al 1995). To combat against damage accrued over hundreds of years, repair mechanisms in sacred lotus seeds must be extraordinarily effective (Priestley 1986;Shen-Miller et al 2002). Moreover, these seeds appeared to have the ability to withstand extremely high temperatures (Ding et al 2008;Ohga 1927).…”

Hyperoside and rutin of Nelumbo nucifera induce mitochondrial apoptosis through a caspase-dependent mechanism in HT-29 human colon cancer cells

“…Nelumbo nucifera, the lotus, is an aquatic perennial plant that is commonly cultivated in water gardens in tropical Asia and Australia (9). The flowers, seeds, young leaves, rhizomes and roots of N. nucifera are used for edible and medicinal sources in Asian regions.…”