An RNA polymerase II- and AGO4-associated protein acts in RNA-directed DNA methylation. [鍏ㄦ枃]

鏈卞仴搴凤紝涓�涓猂NA鑱氬悎閰禝I鍜孉GO4鐩稿叧鐨勮泲鐧芥寚瀵糝NA浠嬪鐨凞NA鐢插熀鍖栥��

浠ヤ笅鏄瀛︾綉鐨勪腑鏂囨姤閬擄細銆婅嚜鐒躲�嬶細涓绉戝瀹跺彂鐜颁笌鍩哄洜鈥滄矇榛樷�濇湁鍏崇壒娈婂熀鍥�

濂ュ湴鍒╂牸闆锋垐灏斅烽棬寰峰皵妞嶇墿鍒嗗瓙鐢熺墿瀛︾爺绌舵墍鏃ュ墠瀹ｅ竷锛屼竴涓寘鎷鐮旂┒鎵�銆佷腑鍥藉悓娴庡ぇ瀛︺�佺編鍥藉姞鍒╃灏间簹澶у绛夋満鏋勭瀛﹀鍦ㄥ唴鐨勫浗闄呯鐮斿皬缁勫彂鐜颁簡涓�绉嶇壒娈婂熀鍥狅紝娌℃湁瀹冿紝妞嶇墿缁嗚優鍐呭叾浠栦竴浜涘熀鍥犲氨鍙兘淇濇寔娌夐粯銆�

鏈�鏂颁竴鏈熻嫳鍥姐�婅嚜鐒躲�嬫潅蹇楃綉缁滅増鍙戣〃浜嗚繖涓浗闄呯鐮斿皬缁勭殑璁烘枃銆傝繖涓�绉戠爺灏忕粍鍙戠幇鐨勭壒娈婂熀鍥犲悕涓篟DM1锛屽畠鍙互缂栫爜鐢熸垚涓�绉嶅皬铔嬬櫧锛屼粠鑰屽弬涓庢寚瀵煎叾浠栧熀鍥犵殑琛ㄨ揪銆�

绉戝瀹舵寚鍑猴紝鍩哄洜涓�鑸浜庤淇濇姢鐘舵�佷腑锛屽彧鏈夐�氳繃鎵�璋撶殑鐢插熀鍖栵紝鍗充笌鐢插熀鎺ヨЕ锛屾墠鑳借〃杈惧苟鍙戞尌浣滅敤銆傚鏋滃幓闄DM1锛岃淇濇姢鐨勫熀鍥犲氨鏃犳硶鐢插熀鍖栵紝涔熷氨鏃犳硶杩涜琛ㄨ揪銆�

鐢变簬姣忎竴涓鐗╃粏鑳炰腑閮藉瓨鍦ㄧ潃瀹屾暣鐨勯仐浼犱俊鎭紝鍥犳蹇呴』璁╂煇浜涘熀鍥犱繚鎸佲�滄矇榛樷�濓紝妞嶇墿鍏蜂綋鐨勫櫒瀹樻墠鑳介『鍒╁湴鍙戞尌鍚勮嚜浣滅敤銆傚惁鍒欙紝鎵�鏈夊熀鍥犲氨浼氶兘鏉ヨ〃杈撅紝妞嶇墿鍣ㄥ畼涔熷皢涓嶇煡閬撳惉浠庤皝鐨勨�滄寚浠も�濄�備竴鑸湪涓�涓鐗╃殑涓婁竾涓熀鍥犻噷锛屽彧鏈夊緢灏戠殑涓�閮ㄥ垎鑳藉琛ㄨ揪锛孯NA锛堟牳绯栨牳閰革級浼氬闇�瑕佽〃杈剧殑鍩哄洜杩涜鏍囪銆俁DM1鍩哄洜鐨勪换鍔″氨鏄RNA鏍囪杩囩殑鍩哄洜琛ㄨ揪銆傜己灏戜簡RDM1锛屾鐗╀腑璁稿鏈琛ㄨ揪鐨勫熀鍥犲氨浼氫繚鎸佲�滄矇榛樷�濓紝妞嶇墿鏃犳硶姝ｅ父鐢熼暱銆�

杩欐槦鏈熸按绋绘枃鐚笉澶氾紝鑹伴毦鍦版墥浜嗗嚑绡囷細

璁℃暟鍣細 Plant J脳1锛孭lant Biotechnol J脳1锛�J Plant Physiol脳1锛孴AG脳1锛孴rends in Plant Science脳2

(===璁哄潧閾炬帴===)

1. Plant J

OsCOL4 is a constitutive flowering repressor upstream of Ehd1 and downstream of OsphyB.

寮�鑺辨姂鍒跺熀鍥燨sCOL4锛屽浜嶦hd涓婃父锛孫sphyB涓嬫父銆�

2. Plant Biotechnol J

Functional analysis of the activation domain of RF2a, a rice transcription factor. [涓嬭浇]

涓�涓按绋昏浆褰曞洜瀛怰F2a鐨勬椿鎬у尯鍩熷垎鏋愩��

3. J Plant Physiol

Exposure of rice seedlings to heat shock protects against subsequent Cd-induced decrease in glutamine synthetase activity and increase in specific protease activity in leaves. [涓嬭浇]

骞艰嫍鐑嚮澶勭悊鍙互鍦ㄥ悗鏈�闃叉闀夎瀵肩殑锛�1锛�璋锋皑閰拌兒鍚堟垚閰舵椿鎬х殑闄嶄綆锛�2锛夌壒瀹氳泲鐧介叾娲绘�х殑澧炲姞銆�

4. Theor Appl Genet

Identification and mapping of PmG16, a powdery mildew resistance gene derived from wild emmer wheat. [涓嬭浇]

灏忛害鐧界矇鐥呮姉鍩哄洜鐨勫畾浣嶃�傛垜涓�鐩村緢鎰熷叴瓒ｅ皬楹︾殑鍩哄洜瀹氫綅鏄拫鍋氱殑銆�

5. Trends inPlant Science

Photorespiration: players, partners and origin [涓嬭浇]

妞嶇墿鍏夊懠鍚哥殑缁艰堪銆�

An engineer’s view on regulation of seed development [涓嬭浇]

绉嶅瓙鍙戣偛鐨勫姩鍔涘璋冩帶銆�(缈昏瘧寰楀涓嶏紵浼间箮鑳介噺鏂归潰鐨勶紝璇ュ拫缈昏瘧锛�)

DNA Methylation Mediated by a MicroRNA Pathway [鍏ㄦ枃] [鎰熻阿绾㈠啗闀垮緛璁哄潧鐨刴hl]

In plants, the known microRNAs (miRNAs) are produced as 锝�21 nucleotide (nt) duplexes from their precursors by Dicer-like 1 (DCL1). They are incorporated into Argonaute 1 (AGO1) protein to regulate target gene expression primarily through mRNA cleavage. We report here the discovery of a class of miRNAs in the model monocot rice (Oryza sativa). These are 24 nt in length and require another member of the Dicer family, DCL3, for their biogenesis. The 24 nt long miRNAs (lmiRNAs) are loaded into AGO4 clade proteins according to hierarchical rules, depending on the upstream biogenesis machinery and the 5鈥�-terminal nucleotide. We demonstrated that lmiRNAs direct DNA methylation at loci from which they are produced as well as in trans at their target genes and play roles in gene regulation. Considered together, our findings define a miRNA pathway that mediates DNA methylation.

Haploid plants produced by centromere-mediated genome elimination 鍏ㄦ枃涓嬭浇

閭ｅぉ鍜屽笀濡硅璁轰絾鍗曞�嶄綋鐨勭函鍜屼紭鍔匡紝姘寸ɑ鍗曞�嶄綋鍩瑰吇涓昏閫氳繃鑺辩矇缁勫煿锛屼絾骞朵笉鏄墍鏈夋鐗╅兘鑳解�滄帴鍙椻�濊繖绉嶆柟寮忋�侼ATURE鐨勮繖绡囨枃绔犳彁渚涗簡涓�涓柊鎬濊矾.cool 锝灺�

鍗曞�嶄綋妞嶇墿锛堜粎浠庝竴涓翰浠ｉ仐浼犳煋鑹蹭綋锛夊湪閬椾紶鐮旂┒涓湁閲嶈浼樺娍锛屽湪妞嶇墿鑲茬涓篃鏋佷负閲嶈鈥斺�斿畠浠鐢ㄦ潵鐢熸垚绾悎瀛愪簩鍊嶄綋锛屼粠鑰岄伩鍏嶅緢澶氫唬鐨勮繎浜茬箒娈栥�傚崟鍊嶄綋鐨勫煿鑲茬洰鍓嶄富瑕�2绉嶆柟寮忥細閰嶅瓙浣撳煿鍏绘垨鑰呬粠灏戦噺绉嶉棿鏉備氦鍙互璇卞鍑烘潵锛屼絾鎬绘湁灞�闄愯寖鍥淬�侻aruthachalam Ravi 鍜� Simon Chan寮�鍙戝嚭涓�绉嶉�氳繃绉嶅瓙鏉ョ敓鎴愬崟鍊嶄綋鎷熷崡鑺ョ殑绠�鍗曟柟娉曪紝璇ユ柟娉曞彲浠ュ緢瀹规槗琚帹骞垮埌鍐滀綔鐗┿��

浠ュ墠锛屽崟鍊嶄綋鐨勭敓鎴愭秹鍙婅繙浜ょ鐨勭粍缁囧煿鍏绘垨鍩哄洜缁勫墧闄わ紝鑰屼笖寰堝鐗╃鐢ㄨ繖浜涙柟娉曟槸涓嶅彲鑳藉煿鑲插嚭鍗曞�嶄綋鐨勩�傛柊鏂规硶娑夊強瀵逛竴绉嶈泲鐧斤紙鍗斥�滅潃涓濈偣鐗瑰紓鎬х粍铔嬬櫧鈥濓紝CENH3锛夌敤鍩哄洜宸ョ▼鏂规硶杩涜澶勭悊锛岀敓鎴愬湪涓庨噹鐢熷瀷鏉備氦鍚庡叾鍩哄洜缁勮浠庡悎瀛愪腑闄ゆ帀鐨勫搧绯汇��

杩欐牱浜х敓鐨勫崟鍊嶄綋妞嶇墿鍙湁鏉ヨ嚜閲庣敓鍨嬩翰浠ｇ殑鏌撹壊浣撱�侰ENH3鍦ㄧ湡鏍哥粏鑳炵潃涓濈偣涓婅捣鏅亶浣滅敤锛屾墍浠ュ師鍒欎笂杩欑鏂规硶鍙互鎺ㄥ箍鍒版墍鏈夋鐗┿��

锘縋roduction of haploid plants that inherit chromosomes from only 聽one parent can greatly accelerate plant breeding. Haploids 聽generated from a heterozygous individual and converted to diploid create instant homozygous lines, bypassing generations of inbreeding. Two methods are generally used to produce haploids. First, 聽cultured gametophyte cells may be regenerated into haploid plants , 聽but many species and genotypes are recalcitrant to this process. 聽Second, haploids can be induced from rare interspecific crosses, in 聽which one parental genome is eliminated after fertilization.The 聽molecular basis for genome elimination is not understood, but one theory posits that centromeres from the two parent species interact 聽unequally with the mitotic spindle, causing selective chromosome 聽loss. Here we show that haploid Arabidopsis thaliana plants can 聽be easily generated through seeds by manipulating a single centromere protein, the centromere-specific histone CENH3 (called 聽CENP-A in human). When cenh3 null mutants expressing altered 聽CENH3 proteins are crossed to wild type, chromosomes from the 聽mutant are eliminated, producing haploid progeny. Haploids are 聽spontaneously converted into fertile diploids through meiotic nonreduction, allowing their genotype to be perpetuated. Maternal and 聽paternal haploids can be generated through reciprocal crosses. We 聽have also exploited centromere-mediated genome elimination to 聽convert a natural tetraploid Arabidopsis into a diploid, reducing 聽its ploidy to simplify breeding. As CENH3 is universal in eukaryotes, 聽our method may be extended to produce haploids in any plant 聽species.

Arabidopsis thaliana life without phytochromes

(===璁哄潧閾炬帴===)

涓�绡囧緢鏈夋剰鎬濈殑鏂囩珷锛屾鐗╂病鏈変簡phytochromes浼氭�庢牱锛熻兘涓嶈兘娲伙紵绛旀鏄紝it depends锛侊紒

Plants use light as a source of energy for photosynthesis and as a source of environmental information perceived by photoreceptors. Testing whether plants can complete their cycle if light provides energy but no information about the environment requires a plant devoid of phytochromes because all photosynthetically active wavelengths activate phytochromes. Producing such a quintuple mutant of Arabidopsis thaliana has been challenging, but we were able to obtain it in the flowering locus T (ft) mutant background. The quintuple phytochrome mutant does not germinate in the FT background, but it germinates to some extent in the ft background. If germination problems are bypassed by the addition of gibberellins, the seedlings of the quintuple phytochrome mutant exposed to red light produce chlorophyll, indicating that phytochromes are not the sole red-light photoreceptors, but they become developmentally arrested shortly after the cotyledon stage. Blue light bypasses this blockage, rejecting the long-standing idea that the blue-light receptors cryptochromes cannot operate without phytochromes. After growth under white light, returning the quintuple phytochrome mutant to red light resulted in rapid senescence of already expanded leaves and severely impaired expansion of new leaves. We conclude that Arabidopsis development is stalled at several points in the presence of light suitable for photosynthesis but providing no photomorphogenic signal.

Enhancement of fruit shelf life by suppressing N-glycan processing enzymes

浣滆�呭彂鐜帮紝鐣寗閲岄潰鐨勪袱涓熀鍥犖憋紞鐢橀湶绯栬嫹閰讹紙伪锛峂an锛夊拰尾锛嶆皑鍩哄繁绯栬嫹閰讹紙尾锛岺ex锛変績杩涚暘鑼勬灉瀹炵殑鎴愮啛杞寲锛岃繖涓や釜鍩哄洜鐨凴NAi妞嶇墿鏄庢樉瑕佹瘮閲庣敓鍨嬭�愪繚瀛�1涓湀涔嬩箙锛岃�岃秴琛ㄨ揪鐨勬鏍垯鍔犲揩浜嗘垚鐔熻蒋鍖栵紝涓旇繖涓や釜鍩哄洜鍙楁鐗╂垚鐔熸墍闇�婵�绱犱箼鐑殑璇卞锛岃浆褰曡氨姣旇緝鍙戠幇鍦≧NAi鐨勬鏍噷锛屼竴浜涚粏鑳炲闄嶈В鍜屾灉瀹炴垚鐔熺浉鍏崇殑鍩哄洜琛ㄨ揪涓嬭皟銆�

In a globalized economy, the control of fruit ripening is of strategic importance because excessive softening limits shelf life. Efforts have been made to reduce fruit softening in transgenic tomato through the suppression of genes encoding cell wall鈥揹egrading proteins. However, these have met with very limited success. N-glycans are reported to play an important role during fruit ripening, although the role of any particular enzyme is yet unknown. We have identified and targeted two ripening-specific N-glycoprotein modifying enzymes, 伪-mannosidase (伪-Man) and 尾-D-N-acetylhexosaminidase (尾-Hex). We show that their suppression enhances fruit shelf life, owing to the reduced rate of softening. Analysis of transgenic tomatoes revealed 鈮�2.5- and 鈮�2-fold firmer fruits in the 伪-Man and 尾-Hex RNAi lines, respectively, and 鈮�30 days of enhanced shelf life. Overexpression of 伪-Man or 尾-Hex resulted in excessive fruit softening. Expression of 伪-Man and 尾-Hex is induced by the ripening hormone ethylene and is modulated by a regulator of ripening, rin (ripening inhibitor). Furthermore, transcriptomic comparative studies demonstrate the down-regulation of cell wall degradation- and ripening-related genes in RNAi fruits. It is evident from these results that N-glycan processing is involved in ripening-associated fruit softening. Genetic manipulation of N-glycan processing can be of strategic importance to enhance fruit shelf life, without any negative effect on phenotype, including yield.

Transcriptional control of gene expression by microRNAs

鎴戜滑鐭ラ亾miRNA鍜屽叾浠栧皬RNA姣斿siRNA涓�鏍凤紝鏄湪杞綍鍚庤皟鎺у熀鍥犺〃杈撅紝浣嗘槸miRNA鍦ㄨ浆褰曟按骞充笂鏄惁璧峰埌璋冩帶浣滅敤涓嶆竻妤氾紝杩欑瘒鏂囩珷浣滆�呭彂鐜帮紝鍦ㄥ皬绮掔钘撴暡闄pDCL1b锛圖ICER-LIKE1b锛夌殑绐佸彉浣撲腑锛宮iRNA鐨勭敓鐗╁悎鎴愪笉鍙楀奖鍝嶏紝浣嗘槸鍓垏闈跺熀鍥犵殑鍔熻兘涓уけ锛岀粨鏋滃鑷翠簡闈跺熀鍥犺浆褰曟湰鐨勪笅闄嶃�傝繖绉嶇獊鍙樹綋鑱氶泦浜嗗ぇ閲忕殑miRNA:target-RNA澶嶅悎浣擄紝瀵艰嚧浜嗛澏鍩哄洜鐨勮秴鐢插熀鍖栵紝杩涜�屼骇鐢熸姂鍒跺熀鍥犺〃杈剧殑鏁堟灉銆傝繖鏉￠�氳矾涔熷彂鐢熷湪閲庣敓鍨嬪彈婵�绱犲鐞嗘椂锛岃繖浜涚粨鏋滆〃鏄庯紝閫氳繃鐢插熀鍖栬捣濮嬫姂鍒跺熀鍥犺〃杈句緷璧栦簬miRNA 鍜屼粬鐨則arget RNA鐨勬瘮渚嬨�傝繖涓彂鐜版剰涔夎繕鏄緢閲嶅ぇ鐨勶紝涔嬪墠璁や负鍦ㄦ鐗╁綋涓紝鐢插熀鍖栧彧鏄笌siRNA鏈夊叧銆�

MicroRNAs (miRNAs) control gene expression in animals and plants. Like another class of small RNAs, siRNAs, they affect gene expression posttranscriptionally. While siRNAs in addition act in transcriptional gene silencing, a role of miRNAs in transcriptional regulation has been less clear. We show here that in moss Physcomitrella patens mutants without a DICER-LIKE1b gene, maturation of miRNAs is normal but cleavage of target RNAs is abolished and levels of these transcripts are drastically reduced. These mutants accumulate miRNA:target-RNA duplexes and show hypermethylation of the genes encoding target RNAs, leading to gene silencing. This pathway occurs also in the wild-type upon hormone treatment. We propose that initiation of epigenetic silencing by DNA methylation depends on the ratio of the miRNA and its target RNA.

Control of Arabidopsis apical鈥揵asal embryo polarity by antagonistic transcription factors

鎴戜滑鐭ラ亾缁嗚優閮芥湁鏋佹�э紝鑳氭洿鏈塧pical鈥揵asal axis锛屽皢鏉ヤ細鍒嗗寲鍑簊hoot/root椤剁鍒嗙敓缁勭粐锛岀洰鍓嶇煡閬撹繖绉嶆瀬鎬ф槸鐢盤LETHORA (PLT) genes鎵�鎺у埗锛岃繖绡囨枃绔�鎵惧埌浜哖LT1 and PLT2鎵�鐩存帴璋冩帶鐨勮浆褰曞叡鎶戝埗瀛怲OPLESS(TPL)锛屽苟涓斿埄鐢═PL浣滀负閬椾紶鏉愭枡锛岃繕鎵惧埌浜咹D-ZIP III瀹舵棌鍩哄洜涔熻捣鐫�閲嶈璋冩帶浣滅敤锛屼粬浠冻鍙互浣縭oot pole into a second shoot pole锛岃繖绡囨枃绔犺鏄庝簡PLT and HD-ZIP III浣滀负鎷姉浣滅敤锛岃皟鑺傜潃root and shoot poles鐨勫垎鍖栥�傝繖绡囨枃绔爁aculty1000缁欎簡9鍒嗭紝寰堥珮鐨勮瘎浠凤紝鎴戝氨鐪嬩簡鎽樿锛屽啓鐨勬垜鑷繁閮界湅涓嶄笅鍘讳簡銆�

Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and organ patterning programs聽 are聽 orchestrated.聽 During聽 Arabidopsis聽 embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical鈥揵asal axis. Recent work has identified the PLETHORA (PLT) genes as master regulators of basal/root fate1鈥�3, whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional corepressor TOPLESS (TPL) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors as master regulators of embryonic
apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles.

鍏充簬妞嶇墿闈炵敓鐗╄儊杩殑妯″瀷鍒嗘瀽/鍙戝睍涓浗瀹跺垎瀛愯偛绉嶉潰涓寸殑鎸戞垬鍜屽睍鏈�

1. Dissection and modelling of abiotic stress tolerance in plants

妞嶇墿闈炵敓鐗╄儊杩殑妯″瀷鍒嗘瀽銆�

2. Molecular breeding in developing countries: challenges and perspectives

鍙戝睍涓浗瀹跺垎瀛愯偛绉嶉潰涓寸殑鎸戞垬鍜屽睍鏈涖�備笉閰嶅浘锛屾憳娈佃窡鍜辩浉鍏崇殑鏂�:

“Tier-1 countries comprising newly industrialised countries (NICs) such as Brazil, China, India, Mexico, South Africa and Thailand substantially invest in technology, R&D and are self-reliant in most aspects of marker technologies. Whilst mid-level developing world economies (tier-2 countries) such as Colombia, Indonesia, Kenya, Morocco, Uruguay and Vietnam are well aware of MB鈥檚 importance, and some effectively apply marker technologies for germplasm characterisation and selection of major genes, low-level economies (tier-3 countries) are struggling to sustain basic breeding.”

Synthetic design of strong promoters

RT锛屽亸閲嶆妧鏈�ф柟闈㈢殑锛屽惎鍔ㄥ瓙璁捐杩囩▼鐨勬枃绔犮��