Thermal-Stable Proteins of Fruit of Long-Living Sacred Lotus Nelumbo nucifera Gaertn var. China Antique

Abstract

Single-seeded fruit of the sacred lotus Nelumbo nucifera Gaertn var. China Antique from NE China have viability as long as ~1300 years determined by direct radiocarbon-dating, having a germination rate of 84%. The pericarp, a fruit tissue that encloses the single seeds of Nelumbo, is considered one of the major factors that contribute to fruit longevity. Proteins that are heat stable and have protective function may be equally important to seed viability. We show proteins of Nelumbo fruit that are able to withstand heating, 31% of which remained soluble in the 110°C-treated embryo-axis of a 549-yr-old fruit and 76% retained fluidity in its cotyledons. Genome of Nelumbo is published. The amino-acid sequences of 11 “thermal proteins” (soluble at 100°C) of modern Nelumbo embryo-axes and cotyledons, identified by mass spectrometry, Western blot and bioassay, are assembled and aligned with those of an archaeal-hyperthermophile Methancaldococcus jannaschii (Mj; an anaerobic methanogen having a growth optimum of 85°C) and with five mesophile angiosperms. These thermal proteins have roles in protection and repair under stress. More than half of the Nelumbo thermal proteins (55%) are present in the archaean Mj, indicating their long-term durability and history. One Nelumbo protein-repair enzyme exhibits activity at 100°C, having a higher heat-tolerance than that of Arabidopsis. A list of 30 sequenced but unassembled thermal proteins of Nelumbo is supplemented.

The complexity of alternative splicing and landscape of tissue-specific expression in lotus (Nelumbo nucifera) unveiled by Illumina- and single-molecule real-time-based RNA-sequencing

“…It is a crucial species in plant phylogenetics study because it is a slowly evolved and early branching eudicot and retained many ancestral phenotypic features similar to monocots 32 , 33 . Besides, it is also an important aquatic horticultural plant, 34 thus increasing the necessity to get a better comprehension of lotus. After the successful sequencing and annotation of the genome of two wild strains of sacred lotus, ‘China Antique’ and ‘Chinese Tai-zi’, 33 , 35 the genome database for ‘China Antique’ has been constructed 36 .…”

Ectopic expression of NnPER1, a Nelumbo nucifera 1‐cysteine peroxiredoxin antioxidant, enhances seed longevity and stress tolerance in Arabidopsis

“…Sacred lotus is an ancient plant and holds the world record of seed longevity (Shen‐Miller et al ., ). Furthermore, the sacred lotus seeds also have strong tolerance to different stress conditions, such as high temperatures (Chu et al ., ; Shen‐Miller et al ., ) and γ‐radiation (Shen‐Miller et al ., ). Because of these features, sacred lotus seeds were supposed to be an excellent genetic resource for the research of seed longevity (Shen‐Miller et al ., ).…”

TMT-based proteomic analysis of the causes of reduced seed viability in Allium mongolicum under accelerated aging

“…HSP proteins can play a crucial protective role in the process of antioxidant damage of seed proteins and can enhance the resistance of seeds to senescence [54]. hsp70 and hsp90 are important chaperone proteins in eukaryotic cells, heat shock protein 70 is involved to the plasma membrane uidity of the cell membrane [55], heat shock protein 90-1-like is involved in stress response processes, mainly involved in cell activity regulation and apoptosis, and the expression of this protein has a positive effect on the stress response [56].…”