Nuclear gene induced plastid alterations in Pennisetum americanum

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 147-151 ◽  
Author(s):  
M. K. Reddy ◽  
N. C. Subrahmanyam

A nonlethal stripe mutant (700430) of Pennisetum americanum was crossed reciprocally with other normal inbred lines to establish its inheritance pattern. A recessive nuclear gene, when homozygous, led to defective plastid development with variable penetrance and expressivity. Intraplant and interspikelet crosses revealed maternal plastid transmission. When stripe plants were crossed with pollen from normal inbreds, green and yellow progeny were obtained; selfing stripe plants or crossing with its green sib produced yellow, stripe, and green progeny. These results suggest that in egg cells with exclusively defective plastids, the plastids do not revert back inspite of acquiring a dominant allele from the pollen parent, while in egg cells with a mixture of green and yellow plastids, the yellow plastids could develop into functional plastids under the influence of a dominant allele.Key words: altered plastids, variable penetrance, plastid transmission, plastid reversion.

2021 ◽  
Vol 22 (5) ◽  
pp. 2512
Author(s):  
Xinwei Wang ◽  
Yaqi An ◽  
Ye Li ◽  
Jianwei Xiao

Chloroplasts cannot develop normally without the coordinated action of various proteins and signaling connections between the nucleus and the chloroplast genome. Many questions regarding these processes remain unanswered. Here, we report a novel P-type pentatricopeptide repeat (PPR) factor, named Albino Cotyledon Mutant1 (ACM1), which is encoded by a nuclear gene and involved in chloroplast development. Knock-down of ACM1 transgenic plants displayed albino cotyledons but normal true leaves, while knock-out of the ACM1 gene in seedlings was lethal. Fluorescent protein analysis showed that ACM1 was specifically localized within chloroplasts. PEP-dependent plastid transcript levels and splicing efficiency of several group II introns were seriously affected in cotyledons in the RNAi line. Furthermore, denaturing gel electrophoresis and Western blot experiments showed that the accumulation of chloroplast ribosomes was probably damaged. Collectively, our results indicate ACM1 is indispensable in early chloroplast development in Arabidopsis cotyledons.


1981 ◽  
Vol 29 (5) ◽  
pp. 617
Author(s):  
MK Rao ◽  
KA Kumari

Rate of cell development in embryo and endosperm during the 1st 4 days after pollination was similar in 2 lines of P. americanum under field conditions. 1st division of the endosperm nucleus was complete within 6 h after pollination. Synchronous mitoses, the mitotic cycle, divisions within the embryo and the endosperm and embryo volume increases are described.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Takumi Arakawa ◽  
Muneyuki Matsunaga ◽  
Katsunori Matsui ◽  
Kanna Itoh ◽  
Yosuke Kuroda ◽  
...  

Abstract Background Cytoplasmic male sterility (CMS) is a widely used trait for hybrid seed production in many crops. Sugar beet CMS is associated with a unique mitochondrial protein named preSATP6 that forms a 250-kDa complex. Restorer-of-fertility 1 (Rf1) is a nuclear gene that suppresses CMS and is, hence, one of the targets of sugar beet breeding. Rf1 has dominant, semi-dominant and recessive alleles, suggesting that it may be a multi-allelic locus; however, the molecular basis for differences in genetic action is obscure. Molecular cloning of Rf1 revealed a gene (orf20) whose protein products produced in transgenics can bind with preSATP6 to generate a novel 200-kDa complex. The complex is also detected in fertility-restored anthers concomitant with a decrease in the amount of the 250-kDa complex. Molecular diversity of the Rf1 locus involves organizational diversity of a gene cluster composed of orf20-like genes (RF-Oma1s). We examined the possibility that members of the clustered RF-Oma1 in this locus could be associated with fertility restoration. Results Six yet uncharacterized RF-Oma1s from dominant and recessive alleles were examined to determine whether they could generate the 200-kDa complex. Analyses of transgenic calli revealed that three RF-Oma1s from a dominant allele could generate the 200-kDa complex, suggesting that clustered RF-Oma1s in the dominant allele can participate in fertility restoration. None of the three copies from two recessive alleles was 200-kDa generative. The absence of this ability was confirmed by analyzing mitochondrial complexes in anthers of plants having these recessive alleles. Together with our previous data, we designed a set of PCR primers specific to the 200-kDa generative RF-Oma1s. The amount of mRNA measured by this primer set inversely correlated with the amount of the 250-kDa complex in anthers and positively correlated with the strength of the Rf1 alleles. Conclusions Fertility restoration by sugar beet Rf1 can involve multiple RF-Oma1s clustered in the locus, implying that stacking 200-kDa generative copies in the locus strengthens the efficacy, whereas the absence of 200-kDa generative copies in the locus makes the allele recessive irrespective of the copy number. We propose that sugar beet Rf1 is a complex locus.


HortScience ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 487-496 ◽  
Author(s):  
Lingli Lou ◽  
Todd C. Wehner

Genes for watermelon [Citrullus lanatus (Thunb.) Matsumura & Nakai] fruit traits have been identified since the 1930s. We conducted a study of fruit traits including fruit stripe width, stripe color, rind color, fruit shape, and blossom end shape (concave vs. convex). Ten watermelon cultivars (inbred lines) were used as parents. Several new genes or alleles were discovered. A series of alleles at the g locus is proposed to explain the inheritance of fruit rind pattern: G (medium or dark solid green), gW (wide stripe), gM (medium stripe), gN (narrow stripe), and g (solid light green or gray). The dominance series is G > gW > gM > gN > g. Another series of alleles at the ob locus is proposed for the fruit shape: allele ObE for elongate fruit, which is the most dominant; allele ObR (not the same as the o gene for round) for the round fruit; and allele ob for oblong fruit, which is the most recessive. Gene csm is proposed for the clear stripe margin in the cultivar Red-N-Sweet and is recessive to the blurred stripe margin (Csm) in ‘Crimson Sweet’, ‘Allsweet’, and ‘Tendersweet Orange Flesh’.


1988 ◽  
Vol 66 (1) ◽  
pp. 179-182 ◽  
Author(s):  
M. K. Reddy ◽  
N. C. Subrahmanyam

The breeding behaviour of the GWS-14 stripe mutant of pearl millet was tested in crosses with different normal inbred lines. The F2 segregations revealed two independently assorting recessive nuclear genes controlling the stripe phenotype with variable expressivity. Striping appeared 25 days after germination or later, suggesting the delayed expression of mutant genes. When stripe plants were crossed with pollen from normal inbreds, normal and white F1 progeny were obtained, while reciprocal crosses gave exclusively normal F1 progeny, suggesting that the white plastids are maternally transmitted in the absence of homozygous recessive nuclear genes in homoplastidic (altered plastids) egg cells. The absence of stripe progeny indicates the possible reversion of such plastids in heteroplastidic egg cells.


2005 ◽  
Vol 9 (5) ◽  
pp. 217-222 ◽  
Author(s):  
Changzheng Huang ◽  
Siyuan Chen ◽  
Zhixiang Liu ◽  
Juan Tao ◽  
Chunsen Wang ◽  
...  

Background: Familial bullous lichen planus (FBLP) is a rare condition. The clinical features dearly have been described. Objective: We report the largest patient series of FBLP and describe its clinical characteristics and inheritance pattern. Methods: In this retrospective chart review, we analyzed nine consecutive familial pedigrees of FBLP with 36 affected individuals who presented to the Department of Dermatology at the Wuhan Union Hospital, a tertiary referral hospital in central China. Parameters analyzed include age of onset, gender predilection, lesional distribution, nail and mucosal involvement, clinical course, and inheritance pattern. Results: Thirty-six of 85 individuals in the nine families were affected (42.4%). Females were more likely to be affected than males (58.3% vs 35.7%, Ġ(χ2 = 3.99. P < 0.05). A bimodal disease onset was found, with one peak at 1–3 years and another at 13–17 years. The shin is the most commonly affected area (97%) followed by the upper limbs and the thighs. Involvement of the torso is relatively rare. Only a minority of cases involves the oral mucosa. The disease tends to follow a chronic and progressive course. The inheritance pattern is autosomal dominant with variable penetrance. Conclusion: Familial bullous lichen planus is a chronic, progressive bullous eruption of the lower and upper extremities. Compared with non familial bullous lichen planus, it has an earlier onset and wider disease distribution. It may be inherited as an autosomal dominant condition with variable penetrance.


1981 ◽  
Vol 29 (5) ◽  
pp. 617
Author(s):  
MK Rao ◽  
KA Kumari

Rate of cell development in embryo and endosperm during the 1st 4 days after pollination was similar in 2 lines of P. americanum under field conditions. 1st division of the endosperm nucleus was complete within 6 h after pollination. Synchronous mitoses, the mitotic cycle, divisions within the embryo and the endosperm and embryo volume increases are described.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 196
Author(s):  
Takayuki Shimizu ◽  
Tatsuru Masuda

Chloroplast biogenesis requires the coordinated expression of the chloroplast and nuclear genomes, which is achieved by communication between the developing chloroplasts and the nucleus. Signals emitted from the plastids, so-called retrograde signals, control nuclear gene expression depending on plastid development and functionality. Genetic analysis of this pathway identified a set of mutants defective in retrograde signaling and designated genomes uncoupled (gun) mutants. Subsequent research has pointed to a significant role of tetrapyrrole biosynthesis in retrograde signaling. Meanwhile, the molecular functions of GUN1, the proposed integrator of multiple retrograde signals, have not been identified yet. However, based on the interactions of GUN1, some working hypotheses have been proposed. Interestingly, GUN1 contributes to important biological processes, including plastid protein homeostasis, through transcription, translation, and protein import. Furthermore, the interactions of GUN1 with tetrapyrroles and their biosynthetic enzymes have been revealed. This review focuses on our current understanding of the function of tetrapyrrole retrograde signaling on chloroplast biogenesis.


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