本帖最后由 choi 于 5-27-2021 09:14 编辑
So far I could not comprehend what Yuan did. The announcement of his death prompted me to do it.
(1) Lin Shih-cheng and Yuan Long-ping, Hybrid Rice Breeding in China. In Innovative Approaches to Rice Breeding; Selected papers from the 1979 International Rice Research Conference. Manila: International Rice Research Institute (1980), 35, 35-36 .
https://books.irri.org/9711040018_content.pdf
("The hybrid rice research program in China was initiated in 1964. Within two years, visual inspection of the panicles during the heading stage revealed several male sterile (MS) rice plants in the fields. These MS plants could be classified into three types: pollen free, pollen abortive, and anther degenerative. * * * Unfortunately, all three types of male sterility were controlled by the recessive nucleus genes. No satisfactory maintainers could be found * * * In the autumn of 1970, a MS wild rice plant was found in nature and was named wild abortive (WA). Its discovery was a breakthrough in hybrid rice breeding. * * * WA designates a MS wild rice plant with abortive pollens. It was found by our co-worker, Li Bi-Hu, in a population of common wild rice (Oryza sativa L. f. spontanea) on Hainan island. WA is a typical photoperiod-sensitive plant * * * But its [WA's] sterility is unstable. At temperatures higher than 30°C, some anthers may bear normal pollens, and consequently a few selfed seeds may be produced")
Note:
(a) Lin Shih-cheng 林世成 (1918-1997; born in 福州市, lived entire life in China, and died in Beijing; his birth might explain English spelling of his given name)
(b) English dictionary:
(i) panicle (n; First Known Use 1577; from Latin pānicula, diminutive of [noun masculine] pānus [ear of millet]): "a compound racemose inflorescence — see INFLORESCENCE ILLUSTRATION"
https://www.merriam-webster.com/dictionary/panicle
(A) When you click "INFLORESCENCE ILLUSTRATION," you see 8 panicle, but also heed 1 raceme. Raceme is a noun and racemose, its corresponding adjective. Then you understand compound raceme. The "compound racemose inflorescence" has racemose to modify inflorescence.
(B) For rice inflorescence, see Gao X-Q et al, Architecture of Wheat Inflorescence: Insights from Rice. Trends in Plant Science, 24: 802 Xin-Qi Gao Ning Wang Xiu-Ling Wang Xian Sheng Zhang Published:June 27, 2019
https://www.cell.com/trends/plant-science/fulltext/S1360-1385(19)30145-1
https://www.researchgate.net/pro ... ights-from-Rice.pdf
(Fig 1: diagram of rice and wheat inflorescences, side by side)
(ii) The noun inflorescence is 花序 in Taiwan.
(iii) florescence (n; Did You Know?: Latin noun masculine flōs flower)
https://www.merriam-webster.com/dictionary/florescence
(c) Wild Abortive 野败 (A mutation must be named somehow.)
(d) Li Bi-Hu 李必湖 (male)
(e) The genus name of rice (Oryza sativa) is from Latin noun feminine oryza rice.
https://en.wiktionary.org/wiki/oryza
, and species name sativa, from Latin adjective masculine satīvus (feminine satīva) sowed, planted.
https://en.wiktionary.org/wiki/sativus
Oryza
https://www.merriam-webster.com/dictionary/Oryza
(pronunciation: the second syllable is pronounced same as rye)
(2) The mitochondrial gene WA352 accounts for rice mutation Wild Abortive.
(a) Ma H, A Battle Between Genomes in Plant Male Fertility. Nature Genetics, 45: 472 (2013)
https://www.nature.com/articles/ng.2618
(b) Luo D et al, A Detrimental Mitochondrial-Nuclear Interaction Causes Cytoplasmic Male Sterility in Rice. Nature Genetics, 45: 573 (2013)
https://www.nature.com/articles/ng.2570
https://www.researchgate.net/pub ... e_sterility_in_rice
Quote:
(i) Abstract: "Here we report that a new mitochondrial gene, WA352 * * * WA352 accumulates preferentially in the anther tapetum, thereby inhibiting COX11 function in peroxide metabolism and triggering premature tapetal programmed cell death and consequent pollen abortion. WA352-induced sterility can be suppressed by two restorer-of-fertility (Rf) genes, suggesting the existence of different mechanisms [which remain elusive to date] to counteract deleterious cytoplasmic factors.
(ii) text:
"In hybrid crop breeding, crossing different inbred lines produces F1 hybrids that usually have higher yields than the parents, a phenomenon known as hybrid vigor or heterosis.
read the following together with viewing Fig 1(a): The authors found "a previously unidentified ORF [acronym for open reading frame, which means a gene encoding a protein] downstream of rpl5 [a gene encoding No 5 of ribosomal proteins in large subunit; a ribosome is made of a a small subunit and a large subunit] comprising three rice mitochondrial genomic segments and one segment of unknown origin (Fig 1a). The 5' region (512 bp [base pairs]) of this ORF is identical to that of a predicted rice mitochondrial ORF, orf284, whereas the 3' region (583 bp) of the ORF is highly similar to that of another predicted rice mitochondrial ORF, orf288; these characteristics suggest that this recombinant structure evolved recently. This chimeric ORF encodes a 352-residue putative protein [ie, the mitochondrial gene WA352 makes a protein of 352 amino acids] with three transmembrane segments (Supplementary Fig 1b [not reproduced in this Web page]) and was thus named WA352 (Wild Abortive 352). * * * WA352 has no similarity to * * * known genes. [In Fig 1(b), a viable pollen is dark brown to black in color whereas rice mutants with WA352 created transparent/ hollow/ inviable pollen.
"CMS-WA can be restored by either of two dominant Rf genes, Rf3 or Rf4 * * * located on chromosomes 1 and 10, respectively [citing two previous reports]. We examined how the Rf genes affect WA352 expression * * * In the Rf4-carrying lines, the amounts of the WA352 * * * transcripts were decreased to ~20–25% of those [without a functional Rf4 gene]" at page 574.
"To trace its origin, we examined WA352 in 17 wild rice species * * * WA352 probably arose 0.7–2 million years ago in an ancestor of O rufipogon * * * The maintenance of WA352 in these species during evolution might be attributed to the widespread presence of Rf gene(s) * * *" at page 576 (while on this page, please also view Fig 4(f) ).
Note:
(i) The article in (2)(a) is not available for free, whose figure, however, is reproduced in
Topic 21.4 The Molecular Mechanism of Cytoplasmic Sterility in Rice. In Taiz L et al, Plant Physiology and Development. 6th ed. Sinauer Associates (an imprint of Oxford Univ Press) (2014).
http://6e.plantphys.net/topic21.04.html
Fig 21.4.A's caption read in part: "Center, the cytoplasmic male sterile (CMS) WA cytoplasm has a rearranged mitochondrial genome, resulting in the production of the WA352 protein, which inhibits OsCOX11 function, resulting in male sterility [through premature programmed cell death in the anther tapetum (without nutritional support, pollens die in infancy)]."
(ii) anther (n; History and Etymology for anther: Ultimately from Ancient Greek [noun neuter] anthos flower)
https://en.wiktionary.org/wiki/ἄνθος):
"— see FLOWER ILLUSTRATION"
https://www.merriam-webster.com/dictionary/anther
(iii) tapetum
https://en.wikipedia.org/wiki/Tapetum
(can refer to tapetum (botany) )
Click "tapetum botany" and one sees the diagram of an anther, which is cylindrical. Why cylindrical? Because that is what an anther (at least in rice) looks like. See ***
(c) Wang X et al, Crystal Structure of WA352 Provides Insight into Cytoplasmic Male Sterility in Rice. Biochemical and Biophysical Research Communications, 501: 898 (2018)
https://pubmed.ncbi.nlm.nih.gov/29775612/
("we report the crystal structure of the C-terminal functional domain of WA352 at 1.3 Å resolution. This functional domain, consisting of five α helices, is spindle-shaped with a length of 42 Å, and a diameter of 28 Å. Notably, the absence of any structural similarity to a known protein structure suggests that the WA352 functional domain is a novel fold")
The report is placed behind paywall. However, authors of the report also deposited their 3-D structure:
5ZT3; Crystal structure of WA352 from Oryza sativa. Protein Data Bank (PDB), Research Collaboratory for Structural Bioinformatics (RCSB, which is jointly run by Rutgers University and UC San Francisco and funded by US grants), May 2018,
https://www.rcsb.org/structure/5ZT3
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