Leaves Don’t Fall; They’re Pushed

first_imgRocks may fall (thus the need for warning signs on highways), but leaves are pushed off of trees by a genetic program.  The process, called abscission, has been mysterious for a long time.  A team from the University of Missouri has mapped out, for the first time, the abscission pathway in one plant.  Being this is the first day of fall, it would be worthwhile to think about the processes behind autumn’s colorful cascade of leaves.    The opening paragraph in PNAS1 shows why leaf fall doesn’t just happen.  Look at just a few of the processes involved:Abscission is a physiological process that involves the programmed separation of entire organs, such as leaves, petals, flowers, and fruit.  Abscission allows plants to discard nonfunctional or infected organs, and promotes dispersion of progeny.  At the cellular level, abscission is the hydrolysis of the middle lamella of an anatomically specialized cell layer, the abscission zone (AZ), by cell wall-modifying and hydrolyzing enzymes.  Thus, abscission requires both the formation of the AZ early in the development of a plant organ and the subsequent activation of the cell separation response.Gene knockout experiments showed that proteins missing from a signalling cascade formed plants deficient in abscission ability.  “A growing paradigm in signal transduction pathways,” they explained, “features receptor modules that perceive signals and modules such as MAPK cascades that relay and amplify this information to downstream effectors.”  Because little is known about this signalling process, they studied it in the common lab plant Arabidopsis (a European/Asian herb also called thale cress).    A press release about the study posted on PhysOrg was titled, “When leaves fall, more is occurring than a change of weather.”  That can be illustrated by the researchers’ ending paragraph.  It shows they uncovered the workings of only a small part of a very complex process:Multiple gene products, including potential signaling ligands, membrane receptors, protein kinase cascades, regulators of hormone responses, and transcription factors have been implicated in the regulation of abscission in plants.  We have demonstrated, by several different lines of evidence, that there is a signaling cascade (Fig. 5B), from putative ligand (IDA) to receptors (HAE HSL2) to cytoplasmic effectors (MKK4, MKK5, MPK3, and MPK6), which function together to control cell separation during abscission.  Additional gene products are also likely to play important roles in abscission and the relationships between them and the signaling pathway outlined here remain to be determined.  However, based on the genetic interactions between IDA, HAE, HSL2, MKK4, and MKK5, it seems that this core signaling cascade is an important regulator of floral abscission.All this for something we take for granted this time of year: colorful leaves drifting by the window.1.  Cho, Larue, Chevalier, Wang, Jinn, Zhang, and Walker, “Regulation of floral organ abscission in Arabidopsis thaliana,” Proceedings of the National Academy of Sciences USA, published online before print September 22, 2008, doi: 10.1073/pnas.0805539105.The autumn leaves drift by my window,The autumn leaves of red and gold;I dream of genes and MAPK modules,Of signal pathways yet scarcely told.When evolutionists continue to proclaim glib generalities about how plants evolved this and animals evolved that, it’s essential to look in detail at some of the structures and processes they’re talking about.  Even something as common as leaf fall is not simple.  The plant has to sense the time of year.  It has to signal the nucleus to translate genes and produce the right proteins in the right quantities.  These form a cascade of signals, with feedback loops, that instigate changes in cell adhesion.  The right cells have to start separating in the right order.  Simultaneously, the photosynthetic organs have to shut down.  The changes in pigments have to be expressed to provide plant protection (10/27/2007).  The stems have to weaken so the leaves will drop only when the plant has enough resources for the coming winter.  These are just a few considerations behind the programmed, coordinated, environmentally-responsive genetic program devoted just to this one operation.    The PhysOrg article tried to explain why leaves fall.  “Aged leaves, for example, may be shed to facilitate the recycling of nutrients, ripening fruits dropped to promote seed dispersal and infected or diseased floral organs discarded to prevent the spread of disease.”  Whoa… that’s teleology-talk.  Stop right there on that first suggestion.  How could a tree plan its own recycling program?  After the leaves have dropped, the nutrients are gone.  They’re lying on the ground.  it doesn’t make any sense to say that the plant facilitated a recycling program, nor that it was trying to promote its own seed dispersal, or trying to prevent the spread of disease.  The plant is a brainless machine programmed with these functions.  If you don’t believe computers can emerge and program themselves, then plants cannot do such things, either.  Such subtle personification fallacies are ubiquitous in evolutionary literature.  Plants do these things because they were programmed to do them.    Many questions remain.  How does the whole plant know to change color all at once?  Since abscission also relates to fruit and seed dispersal, how does the abscission program know when the seed ripening program has completed?  How do the stems on maple seeds loosen at precisely the time when the seeds, that work like marvelous propellers in the wind, are ready to fly?  Let’s teach our kids to see beyond the surface properties of nature into its marvelous secrets.  This is good inoculation against dogmas that would have them believe complex programmed operations just happen.    Suggested visual resources: Journey of Life and Wonders of God’s Creation from Moody Video, and Incredible Creatures that Defy Evolution from Exploration Films.  Or, take a walk in the woods for a 360-degree, surround-sound demonstration.(Visited 20 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Read More

5 PH footballers begin camp, nurse dreams of trip to Munich

first_imgView comments The five were chosen after the National Youth Futsal Cup organized by Allianz PNB Life, PFF and Henry V. Moran Foundation last May.The four-day AJFC, now on its ninth edition but with the Philippines in the lineup just this year, is being held at Finns Recreation Club under the supervision of FC Bayern coaches led by Klaus Augenthaler and retired striker and AJFC ambassador Giovane Elber.“Have fun and enjoy,” Sollorin remembered the coaches telling them.Indonesia, China, Malaysia, Laos, Sri Lanka, Thailand and Singapore also sent their players aged 14 to 16. The final cast will fly to Munich on Aug. 17 to 22 to meet the FC Bayern players, train under the coaches of the German club and watch the Bundesliga 2017-2018 opening match at Allianz Arena.One participant will also get the Good Sportsmanship award which is equivalent to a one-week scholarship later this year at Aspire Academy, an internationally-renowned sports institution in Doha, Qatar.ADVERTISEMENT Robredo should’ve resigned as drug czar after lack of trust issue – Panelo “They get shy around the other kids,” said Landagan. “At the same time, they’re still very playful.”“I told them to interact with the other kids and assert themselves on the field,” he added.FEATURED STORIESSPORTSSEA Games: Biñan football stadium stands out in preparedness, completionSPORTSPrivate companies step in to help SEA Games hostingSPORTSWin or don’t eat: the Philippines’ poverty-driven, world-beating pool starsKonrad Keim Sollorin of Ateneo de Iloilo, Aeron Tenollar of Baguio City, JM Mitra of De La Salle Zobel and Gawad Kalinga Football Program’s Jasper Beruan and Jeofrey Fresado arrived here Monday and began camp the following day.They were accompanied by Allianz PNB Life brand director Rei Abrazaldo. Mitra’s parents and Sollorin’s father are also here. Former FC Bayern Munich striker Giovane Elber (fourth from left) joins PH’s Konrad Keim Sollorin, JM Mitra, Jasper Beruan. Aeron Tenollar and Jeofrey Fresado at theAllianz Junior Football Camp at Finns Recreation Club in Bali, Indonesia.BALI, INDONESIA—More than skills training and the much-coveted trip to the FC Bayern junior camp in Munich, Germany, camp directors want the 49 teenage players participating in a football clinic here to learn teamwork and improve on their character.Coach Jess Landagan of the Philippine Football Federation (PFF) said the five Filipino players, all aged 14, at the ongoing Allianz Junior Football Camp (AJFC) have yet to overcome their timidness and develop concentration.ADVERTISEMENT Don’t miss out on the latest news and information. Church, environmentalists ask DENR to revoke ECC of Quezon province coal plant FEU Auditorium’s 70th year celebrated with FEU Theater Guild’s ‘The Dreamweavers’ Trump strips away truth with hunky topless photo tweet Lacson: SEA Games fund put in foundation like ‘Napoles case’center_img Sports Related Videospowered by AdSparcRead Next MOST READ National Coffee Research Development and Extension Center brews the 2nd National Coffee Education Congress Trending Articles PLAY LIST 00:50Trending Articles00:50Trending Articles00:50Trending Articles02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City01:07Trump talks impeachment while meeting NCAA athletes02:49World-class track facilities installed at NCC for SEA Games DILG, PNP back suspension of classes during SEA Games LATEST STORIES Ethel Booba on hotel’s clarification that ‘kikiam’ is ‘chicken sausage’: ‘Kung di pa pansinin, baka isipin nila ok lang’ Battle on top: SMB, Star collidelast_img read more

Read More

George Powers Thunder Past Bucks, Earns Giannis’ Praise

first_imgOKLAHOMA CITY (AP) — OKLAHOMA CITY (AP) — Paul George delivered once again for Oklahoma City.Even Giannis Antetokounmpo was impressedGeorge had 36 points and 13 rebounds, and the Thunder beat Antetokounmpo and the Milwaukee Bucks 118-112 on Sunday for their fifth straight victory.George, an All-Star starter, scored seven points in the final 1:15 to help the Thunder hold off the team with the NBA’s best record. As he stood at the free-throw line late in the game, the M-V-P chants that had been reserved for Russell Westbrook in recent years rained down on George.“He was doing everything,” said Antetokounmpo, another All-Star starter. “Making 3s, mid-range, dunking, floaters. It was a little of everything. He was playing amazing. Down the stretch, you know where the ball’s going to go. It’s going to go to Paul George, and he closed the game out for them and he played the right way.”Westbrook had 13 points, 13 rebounds and 11 assists for his 16th triple-double of the season and No. 120 for his career. Jerami Grant scored 16 points and Terrance Ferguson added 15 for the Thunder.Antetokounmpo had 27 points and 18 rebounds for Milwaukee, and Khris Middleton added 22 points.Eric Bledsoe hit a 3-pointer with just over a minute left to cut Oklahoma City’s lead to three, but George drained a 3-pointer in Malcolm Brogdon’s face at the end of the shot clock to push the margin back up to six.“I’ve got a smaller guy on me,” George said. “Just shoot over the top. Just took advantage of that.”George scored 21 points in the first half to help the Thunder take a 56-42 lead. Antetokounmpo missed all six of his shots before the break and scored just three points.“Giannis had some good looks he normally makes, he didn’t make, but then I think individually they were good on him,” Bucks coach Mike Budenholzer said. “Jerami Grant and then a few other guys take the challenge individually. A lot of help. Guys are swarming him, so credit to them.”Steven Adams, Oklahoma City’s lumbering 7-foot center, got the crowd amped up with a surprise early in the third quarter. He got a steal, dribbled three quarters of the way down the court and converted a layup to give the Thunder a 64-52 lead.The Thunder led 82-66 before the Bucks hit three straight 3-pointers, including two from Middleton. Oklahoma City held on to lead 89-79 at the end of the third quarter.ROCKETS 103, MAGIC 98HOUSTON (AP) — James Harden scored 40 points, and Houston rallied for the win in Chris Paul’s return from a hamstring injury.Houston trailed by as many as 16. The game was tied with about 75 seconds left when a 3-pointer by Harden put the Rockets up 98-95. Terrence Ross missed a 3 on the other end and Harden added a step-back jumper with 30 seconds left.Harden got his third block when he swatted away a shot by Evan Fournier, and Paul added two free throws with 13.6 seconds remaining to secure Houston’s third straight victory. Paul had 12 points and six assists after missing the previous 17 games with a strained left hamstring.Aaron Gordon had 23 points for the Magic, who have dropped six of seven.RAPTORS 123, MAVERICKS 120DALLAS (AP) — Kawhi Leonard scored 33 points to help Toronto overcome a triple-double from Dallas rookie Luka Doncic.Pascal Siakam’s three-point play snapped a 108-108 tie with 3:56 remaining as the Raptors recovered from a seven-point deficit early in the fourth quarter.Doncic, who turns 20 on Feb. 28, had 35 points, 12 rebounds and 10 assists to become the first teenager in NBA history with two triple-doubles.Kyle Lowry scored 19 points for Toronto and Siakam had 14.JAZZ 125, TIMBERWOLVES 111MINNEAPOLIS (AP) — Donovan Mitchell had 29 points for surging Utah, and Ricky Rubio added 18 points and eight assists.After going 2 of 12 in the first half, Mitchell scored 13 points in the third quarter to help hold off a Minnesota rally and give the Jazz their ninth win in 10 games. Utah shot 71 percent (27 of 38) during the second half for its second victory in three nights over the Timberwolves.Andrew Wiggins led Minnesota with 35 points, and Karl-Anthony Towns added 22. Jerryd Bayless had a season-high 19.Rudy Gobert had 17 points for Utah.SPURS 132, WIZARDS 119SAN ANTONIO (AP) — LaMarcus Aldridge had 30 points, nine rebounds and six assists, powering San Antonio to the victory.The Spurs were without leading scorer DeMar DeRozan, but had seven players in double figures. Reserve Davis Bertans had a season-high 21 points after missing the previous two games due to personal reasons. Derrick White and Bryn Forbes added 16 points each.Washington, which had won five of seven, lost its 19th straight in San Antonio. Bradley Beal and Tomas Satoransky each scored 21 points.CLIPPERS 122, KINGS 108LOS ANGELES (AP) — Montrezl Harrell scored 25 points, and the Clippers earned their third consecutive win.Tobias Harris added 18 points for Los Angeles, which was coming off a 3-1 road trip. Lou Williams had 12 points and 10 assists.The Clippers had 35 assists on 42 field goals.De’Aaron Fox led Sacramento with 21 points. Bogdan Bogdanovic added 19 points, and Willie Cauley-Stein had 12 rebounds.HEAT 106, KNICKS 97NEW YORK (AP) — Wayne Ellington scored each of his 19 points in the second half, and the Heat handed the Knicks their ninth straight loss.Miami had seven players score in double figures in its second straight win. Dwyane Wade had 15 points and 10 assists, and Hassan Whiteside finished with 13 points and 16 rebounds.Wade, who plans to retire at the end of the season, received a standing ovation from the Madison Square Garden crowd when he was taken out in the final seconds.Tim Hardaway Jr. scored 22 points for New York, and Trey Burke had 16.Former Knicks star Carmelo Anthony watched from a courtside seat and waved to the cheering crowd when he was acknowledged on the scoreboard in the first quarter.CAVALIERS 104, BULLS 101CHICAGO (AP) — Jordan Clarkson and Alec Burks each scored 18 points, and the Cavaliers ended a six-game losing streak.NBA-worst Cleveland (10-41) had dropped 18 of 19. Cedi Osman scored 17 points, and Matthew Dellavedova finished with 16.Lauri Markkanen led Chicago with 21 points and 15 rebounds, and Zach LaVine had 17 points and 12 rebounds. The Bulls (11-39) have lost three straight and 13 of 14.Rodney Hood had a follow basket with 17 seconds left to put Cleveland up 102-101. After a Chicago miss, Dellavedova hit a pair of free throws. LaVine missed a 3-point attempt at the buzzer.LAKERS 116, SUNS 102LOS ANGELES (AP) — Ivica Zubac and Kentavious Caldwell-Pope each scored 24 points and the short-handed Lakers led throughout in a victory over the Phoenix Suns.Brandon Ingram added 22 points as Los Angeles was missing Kyle Kuzma (hip) and Tyson Chandler (rest), along with LeBron James and Lonzo Ball. Still, the Lakers dominated the inside against a small Phoenix lineup as it had a 70-46 advantage in points in the paint.Devin Booker scored 21 points, Kelly Oubre Jr. added 17 and Mikal Bridges 16 for Phoenix, which has dropped eight straight for its second-longest losing streak of the season. The Suns dropped 10 in a row from Nov. 25 to Dec. 11.Phoenix’s Deandre Ayton missed his fifth straight game with a sprained left ankle.___TweetPinShare0 Shareslast_img read more

Read More